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QGIS/src/providers/postgres/qgspostgresprovider.cpp

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/***************************************************************************
qgspostgresprovider.cpp - QGIS data provider for PostgreSQL/PostGIS layers
-------------------
begin : 2004/01/07
copyright : (C) 2004 by Gary E.Sherman
email : sherman at mrcc.com
***************************************************************************/
/***************************************************************************
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
***************************************************************************/
/* $Id$ */
#include <fstream>
#include <iostream>
#include <cassert>
#include <QStringList>
#include <QApplication>
#include <QMessageBox>
#include <QEvent>
#include <QCustomEvent>
#include <QTextOStream>
#include <QRegExp>
#include <QMap>
// for ntohl
#ifdef WIN32
#include <winsock.h>
#else
#include <netinet/in.h>
#endif
#include <qgis.h>
#include <qgsfeature.h>
#include <qgsfield.h>
#include <qgsrect.h>
#include <qgsmessageviewer.h>
#include "qgsprovidercountcalcevent.h"
#include "qgsproviderextentcalcevent.h"
#include "qgspostgresprovider.h"
#include "qgspostgrescountthread.h"
#include "qgspostgresextentthread.h"
#include "qgspostgisbox3d.h"
#include "qgslogger.h"
#ifdef WIN32
#define QGISEXTERN extern "C" __declspec( dllexport )
#else
#define QGISEXTERN extern "C"
#endif
const QString POSTGRES_KEY = "postgres";
const QString POSTGRES_DESCRIPTION = "PostgreSQL/PostGIS data provider";
QgsPostgresProvider::QgsPostgresProvider(QString const & uri)
: QgsVectorDataProvider(uri),
geomType(QGis::WKBUnknown),
gotPostgisVersion(FALSE)
{
// assume this is a valid layer until we determine otherwise
valid = true;
/* OPEN LOG FILE */
// Make connection to the data source
// For postgres, the connection information is passed as a space delimited
// string:
// host=192.168.1.5 dbname=test port=5342 user=gsherman password=xxx table=tablename
// A little bit of backwards compability. At r6193 the schema/table
// names became fully quoted, but with the problem that earlier
// project files then didn't load. This bit of code puts in the
// quotes that are now required.
QString uriModified = uri;
int start = uriModified.indexOf("table=\"");
if (start == -1)
{
// Need to put in some "'s
start = uriModified.indexOf("table=");
uriModified.insert(start+6, '"');
int start_dot = uriModified.indexOf('.', start+7);
if (start_dot != -1)
{
uriModified.insert(start_dot, '"');
uriModified.insert(start_dot+2, '"');
}
// and one at the end
int end = uriModified.indexOf(' ',start);
if (end != -1)
uriModified.insert(end, '"');
}
// Strip the table and sql statement name off and store them
int sqlStart = uriModified.find(" sql");
int tableStart = uriModified.find("table=");
#ifdef QGISDEBUG
qDebug( "****************************************");
qDebug( "**** Postgresql Layer Creation *****" );
qDebug( "****************************************");
qDebug( (const char*)(QString("URI: ") + uriModified).toLocal8Bit().data() );
QString msg;
qDebug( "tableStart: " + msg.setNum(tableStart) );
qDebug( "sqlStart: " + msg.setNum(sqlStart));
#endif
mTableName = uriModified.mid(tableStart + 6, sqlStart - tableStart -6);
if(sqlStart > -1)
{
sqlWhereClause = uriModified.mid(sqlStart + 5);
}
else
{
sqlWhereClause = QString::null;
}
QString connInfo = uriModified.left(uriModified.find("table="));
#ifdef QGISDEBUG
qDebug( (const char*)(QString("Table name is ") + mTableName).toLocal8Bit().data());
qDebug( (const char*)(QString("SQL is ") + sqlWhereClause).toLocal8Bit().data() );
qDebug( "Connection info is " + connInfo);
#endif
// Pick up some stuff from the uriModified: basically two bits of text
// inside double quote marks, separated by a .
QRegExp reg("\"(.+)\"\\.\"(.+)\".+\\((.+)\\)");
reg.indexIn(mTableName);
QStringList stuff = reg.capturedTexts();
mSchemaName = stuff[1];
mTableName = stuff[2];
geometryColumn = stuff[3];
// Keep a schema qualified table name for convenience later on.
if (mSchemaName.length() > 0)
mSchemaTableName = "\"" + mSchemaName + "\".\"" + mTableName + "\"";
else
mSchemaTableName = "\"" + mTableName + "\"";
/* populate the uri structure */
mUri.schema = mSchemaName;
mUri.table = mTableName;
mUri.geometryColumn = geometryColumn;
mUri.sql = sqlWhereClause;
// parse the connection info
QStringList conParts = QStringList::split(" ", connInfo);
QStringList parm = QStringList::split("=", conParts[0]);
if(parm.size() == 2)
{
mUri.host = parm[1];
}
parm = QStringList::split("=", conParts[1]);
if(parm.size() == 2)
{
mUri.database = parm[1];
}
parm = QStringList::split("=", conParts[2]);
if(parm.size() == 2)
{
mUri.port = parm[1];
}
parm = QStringList::split("=", conParts[3]);
if(parm.size() == 2)
{
mUri.username = parm[1];
}
// The password can have '=' and ' ' characters in it, so we can't
// use the split on '=' and ' ' technique - use indexOf()
// instead.
QString key="password='";
int i = connInfo.indexOf(key);
if (i != -1)
{
QString password = connInfo.mid(i+key.length());
// Now walk through the string till we find a ' character, but
// need to allow for an escaped ' character (which will be the
// \' character pair).
int n = 0;
bool escaped = false;
while (n < password.length() && (password[n] != '\'' || escaped))
{
if (password[n] == '\\')
escaped = true;
else
escaped = false;
n++;
}
// The -1 is to remove the trailing ' character
mUri.password = password.left(n);
}
else
/* end uri structure */
QgsDebugMsg("Geometry column is: " + geometryColumn);
QgsDebugMsg("Schema is: " + mSchemaName);
QgsDebugMsg("Table name is: " + mTableName);
//QString logFile = "./pg_provider_" + mTableName + ".log";
//pLog.open((const char *)logFile);
QgsDebugMsg("Opened log file for " + mTableName);
PGconn *pd = PQconnectdb((const char *) connInfo);
// check the connection status
if (PQstatus(pd) == CONNECTION_OK)
{
// store the connection for future use
connection = pd;
//set client encoding to unicode because QString uses UTF-8 anyway
QgsDebugMsg("setting client encoding to UNICODE");
int errcode=PQsetClientEncoding(connection, "UNICODE");
#ifdef QGISDEBUG
if(errcode==0)
{
qWarning("encoding successfully set");
}
else if(errcode==-1)
{
qWarning("error in setting encoding");
}
else
{
qWarning("undefined return value from encoding setting");
}
#endif
QgsDebugMsg("Checking for select permission on the relation");
// Check that we can read from the table (i.e., we have
// select permission).
QString sql = "select * from " + mSchemaTableName + " limit 1";
PGresult* testAccess = PQexec(pd, (const char*)(sql.utf8()));
if (PQresultStatus(testAccess) != PGRES_TUPLES_OK)
{
showMessageBox(tr("Unable to access relation"),
tr("Unable to access the ") + mSchemaTableName +
tr(" relation.\nThe error message from the database was:\n") +
QString(PQresultErrorMessage(testAccess)) + ".\n" +
"SQL: " + sql);
PQclear(testAccess);
valid = false;
return;
}
PQclear(testAccess);
/* Check to see if we have GEOS support and if not, warn the user about
the problems they will see :) */
QgsDebugMsg("Checking for GEOS support");
if(!hasGEOS(pd))
{
showMessageBox(tr("No GEOS Support!"),
tr("Your PostGIS installation has no GEOS support.\n"
"Feature selection and identification will not "
"work properly.\nPlease install PostGIS with "
"GEOS support (http://geos.refractions.net)"));
}
//QgsDebugMsg("Connection to the database was successful");
if (getGeometryDetails()) // gets srid and geometry type
{
deduceEndian();
calculateExtents();
getFeatureCount();
// Populate the field vector for this layer. The field vector contains
// field name, type, length, and precision (if numeric)
sql = "select * from " + mSchemaTableName + " limit 1";
PGresult* result = PQexec(pd, (const char *) (sql.utf8()));
//QgsDebugMsg("Field: Name, Type, Size, Modifier:");
for (int i = 0; i < PQnfields(result); i++)
{
QString fieldName = PQfname(result, i);
int fldtyp = PQftype(result, i);
QString typOid = QString().setNum(fldtyp);
int fieldModifier = PQfmod(result, i);
sql = "select typelem from pg_type where typelem = " + typOid + " and typlen = -1";
//QgsDebugMsg(sql);
PGresult *oidResult = PQexec(pd, (const char *) sql);
// get the oid of the "real" type
QString poid = PQgetvalue(oidResult, 0, PQfnumber(oidResult, "typelem"));
PQclear(oidResult);
sql = "select typname, typlen from pg_type where oid = " + poid;
//QgsDebugMsg(sql);
oidResult = PQexec(pd, (const char *) sql);
QString fieldType = PQgetvalue(oidResult, 0, 0);
QString fieldSize = PQgetvalue(oidResult, 0, 1);
PQclear(oidResult);
sql = "select oid from pg_class where relname = '" + mTableName + "' and relnamespace = ("
"select oid from pg_namespace where nspname = '" + mSchemaName + "')";
PGresult *tresult= PQexec(pd, (const char *)(sql.utf8()));
QString tableoid = PQgetvalue(tresult, 0, 0);
PQclear(tresult);
sql = "select attnum from pg_attribute where attrelid = " + tableoid + " and attname = '" + fieldName + "'";
tresult = PQexec(pd, (const char *)(sql.utf8()));
QString attnum = PQgetvalue(tresult, 0, 0);
PQclear(tresult);
QgsDebugMsg("Field: " + attnum + " maps to " + QString::number(i) + " " + fieldName + ", " +
fieldType + " (" + QString::number(fldtyp) + "), " + fieldSize + ", " + QString::number(fieldModifier));
attributeFieldsIdMap[attnum.toInt()] = i;
if(fieldName!=geometryColumn)
{
attributeFields.push_back(QgsField(fieldName, fieldType, fieldSize.toInt(), fieldModifier));
}
}
PQclear(result);
// set the primary key
getPrimaryKey();
// Set the postgresql message level so that we don't get the
// 'there is no transaction in progress' warning.
#ifndef QGISDEBUG
PQexec(connection, "set client_min_messages to error");
#endif
// Kick off the long running threads
#ifdef POSTGRESQL_THREADS
QgsDebugMsg("QgsPostgresProvider: About to touch mExtentThread");
mExtentThread.setConnInfo( connInfo );
mExtentThread.setTableName( mTableName );
mExtentThread.setSqlWhereClause( sqlWhereClause );
mExtentThread.setGeometryColumn( geometryColumn );
mExtentThread.setCallback( this );
QgsDebugMsg("QgsPostgresProvider: About to start mExtentThread");
mExtentThread.start();
QgsDebugMsg("QgsPostgresProvider: Main thread just dispatched mExtentThread");
QgsDebugMsg("QgsPostgresProvider: About to touch mCountThread");
mCountThread.setConnInfo( connInfo );
mCountThread.setTableName( mTableName );
mCountThread.setSqlWhereClause( sqlWhereClause );
mCountThread.setGeometryColumn( geometryColumn );
mCountThread.setCallback( this );
QgsDebugMsg("QgsPostgresProvider: About to start mCountThread");
mCountThread.start();
QgsDebugMsg("QgsPostgresProvider: Main thread just dispatched mCountThread");
#endif
}
else
{
// the table is not a geometry table
numberFeatures = 0;
valid = false;
QgsDebugMsg("Invalid Postgres layer");
}
ready = false; // not ready to read yet cuz the cursor hasn't been created
} else {
valid = false;
//QgsDebugMsg("Connection to database failed");
}
//fill type names into lists
mNumericalTypes.push_back("double precision");
mNumericalTypes.push_back("int4");
mNumericalTypes.push_back("int8");
mNonNumericalTypes.push_back("text");
mNonNumericalTypes.push_back("varchar(30)");
if (primaryKey.isEmpty())
{
valid = false;
}
// Close the database connection if the layer isn't going to be loaded.
if (!valid)
PQfinish(connection);
}
QgsPostgresProvider::~QgsPostgresProvider()
{
#ifdef POSTGRESQL_THREADS
QgsDebugMsg("QgsPostgresProvider: About to wait for mExtentThread");
mExtentThread.wait();
QgsDebugMsg("QgsPostgresProvider: Finished waiting for mExtentThread");
QgsDebugMsg("QgsPostgresProvider: About to wait for mCountThread");
mCountThread.wait();
QgsDebugMsg("QgsPostgresProvider: Finished waiting for mCountThread");
// Make sure all events from threads have been processed
// (otherwise they will get destroyed prematurely)
QApplication::sendPostedEvents(this, QGis::ProviderExtentCalcEvent);
QApplication::sendPostedEvents(this, QGis::ProviderCountCalcEvent);
#endif
PQfinish(connection);
QgsDebugMsg("QgsPostgresProvider: deconstructing.");
//pLog.flush();
}
QString QgsPostgresProvider::storageType()
{
return "PostgreSQL database with PostGIS extension";
}
//TODO - we may not need this function - consider removing it from
// the dataprovider.h interface
/**
* Get the first feature resutling from a select operation
* @return QgsFeature
*/
//TODO - this function is a stub and always returns 0
QgsFeature *QgsPostgresProvider::getFirstFeature(bool fetchAttributes)
{
QgsFeature *f = 0;
if (valid) {
//QgsDebugMsg("getting first feature");
f = new QgsFeature();
/* f->setGeometry(getGeometryPointer(feat));
if(fetchAttributes){
getFeatureAttributes(feat, f);
} */
}
return f;
}
bool QgsPostgresProvider::getNextFeature(QgsFeature &feature, bool fetchAttributes)
{
return true;
}
/**
* Get the next feature resutling from a select operation
* Return 0 if there are no features in the selection set
* @return QgsFeature
*/
QgsFeature *QgsPostgresProvider::getNextFeature(bool fetchAttributes)
{
QgsFeature *f = 0;
int row = 0; // TODO: Make this useful
if (valid){
QString fetch = "fetch forward 1 from qgisf";
queryResult = PQexec(connection, (const char *)fetch);
// std::cerr << "Error: " << PQerrorMessage(connection) << std::endl;
// std::cerr << "Fetched " << PQntuples(queryResult) << "rows" << std::endl;
if(PQntuples(queryResult) == 0){
if (ready)
PQexec(connection, "end work");
ready = false;
return 0;
}
// QgsDebugMsg("Raw value of the geometry field: " + PQgetvalue(queryResult,0,PQfnumber(queryResult,"qgs_feature_geometry")));
//QgsDebugMsg("Length of oid is " + PQgetlength(queryResult,0, PQfnumber(queryResult,"oid")));
// get the value of the primary key based on type
int oid = *(int *)PQgetvalue(queryResult, row, PQfnumber(queryResult,"\""+primaryKey+"\""));
// QgsDebugMsg("OID from database: " + QString::number(oid));
if (swapEndian)
oid = ntohl(oid); // convert oid to opposite endian
// oid is the key to be used in fetching attributes if
// fetchAttributes = true
//QgsDebugMsg("Using OID: " + QString::number(oid));
f = new QgsFeature(oid);
if (fetchAttributes)
getFeatureAttributes(oid, row, f);
int returnedLength = PQgetlength(queryResult, row, PQfnumber(queryResult,"qgs_feature_geometry"));
//--std::cerr << __FILE__ << ":" << __LINE__ << " Returned length is " << returnedLength << std::endl;
if(returnedLength > 0)
{
unsigned char *feature = new unsigned char[returnedLength + 1];
memset(feature, '\0', returnedLength + 1);
memcpy(feature, PQgetvalue(queryResult, row, PQfnumber(queryResult,"qgs_feature_geometry")), returnedLength);
#ifdef QGISDEBUG
// a bit verbose
//int wkbType = *((int *) (feature + 1));
//QgsDebugMsg("WKBtype is: " + QString::number(wkbType));
#endif
f->setGeometryAndOwnership(feature, returnedLength + 1);
}
else
{
//QgsDebugMsg("Couldn't get the feature geometry in binary form");
}
PQclear(queryResult);
}
else
{
//QgsDebugMsg("Read attempt on an invalid postgresql data source");
}
return f;
}
// // TODO: Remove completely (see morb_au)
// QgsFeature* QgsPostgresProvider::getNextFeature(std::list<int> const & attlist)
// {
// return getNextFeature(attlist, 1);
// }
QgsFeature* QgsPostgresProvider::getNextFeature(std::list<int> const & attlist, int featureQueueSize)
{
QgsFeature *f = 0;
if (valid)
{
// Top up our queue if it is empty
if (mFeatureQueue.empty())
{
if (featureQueueSize < 1)
{
featureQueueSize = 1;
}
QString fetch = QString("fetch forward %1 from qgisf")
.arg(featureQueueSize);
queryResult = PQexec(connection, (const char *)fetch);
int rows = PQntuples(queryResult);
if (rows == 0)
{
QgsDebugMsg("End of features.");
if (ready)
PQexec(connection, "end work");
ready = false;
return 0;
}
for (int row = 0; row < rows; row++)
{
int oid = *(int *)PQgetvalue(queryResult, row, PQfnumber(queryResult,"\""+primaryKey+"\""));
//QgsDebugMsg("Primary key type is " + primaryKeyType);
if (swapEndian)
oid = ntohl(oid); // convert oid to opposite endian
f = new QgsFeature(oid);
if(!attlist.empty())
{
getFeatureAttributes(oid, row, f, attlist);
}
int returnedLength = PQgetlength(queryResult, row, PQfnumber(queryResult,"qgs_feature_geometry"));
if(returnedLength > 0)
{
unsigned char *feature = new unsigned char[returnedLength + 1];
memset(feature, '\0', returnedLength + 1);
memcpy(feature, PQgetvalue(queryResult, row, PQfnumber(queryResult,"qgs_feature_geometry")), returnedLength);
// Too verbose
//int wkbType = *((int *) (feature + 1));
//QgsDebugMsg("WKBtype is: " + QString::number(wkbType));
f->setGeometryAndOwnership(feature, returnedLength + 1);
}
else
{
//QgsDebugMsg("Couldn't get the feature geometry in binary form");
}
// QgsDebugMsg("QgsPostgresProvider::getNextFeature: pushing " + QString::number(f->featureId()));
mFeatureQueue.push(f);
} // for each row in queue
// QgsDebugMsg("QgsPostgresProvider::getNextFeature: retrieved batch of features.");
PQclear(queryResult);
} // if new queue is required
// Now return the next feature from the queue
f = mFeatureQueue.front();
mFeatureQueue.pop();
}
else
{
//QgsDebugMsg("Read attempt on an invalid postgresql data source");
}
//QgsDebugMsg("QgsPostgresProvider::getNextFeature: returning " + QString::number(f->featureId()));
return f;
}
/**
* Select features based on a bounding rectangle. Features can be retrieved
* with calls to getFirstFeature and getNextFeature.
* @param mbr QgsRect containing the extent to use in selecting features
*/
void QgsPostgresProvider::select(QgsRect * rect, bool useIntersect)
{
// spatial query to select features
QgsDebugMsg("Selection polygon is " + rect->asPolygon());
QString declare = QString("declare qgisf binary cursor for select \""
+ primaryKey
+ "\",asbinary(\"%1\",'%2') as qgs_feature_geometry from %3").arg(geometryColumn).arg(endianString()).arg(mSchemaTableName);
QgsDebugMsg("Binary cursor: " + declare);
if(useIntersect){
// declare += " where intersects(" + geometryColumn;
// declare += ", GeometryFromText('BOX3D(" + rect->asWKTCoords();
// declare += ")'::box3d,";
// declare += srid;
// declare += "))";
// Contributed by #qgis irc "creeping"
// This version actually invokes PostGIS's use of spatial indexes
declare += " where " + geometryColumn;
declare += " && setsrid('BOX3D(" + rect->asWKTCoords();
declare += ")'::box3d,";
declare += srid;
declare += ")";
declare += " and intersects(" + geometryColumn;
declare += ", setsrid('BOX3D(" + rect->asWKTCoords();
declare += ")'::box3d,";
declare += srid;
declare += "))";
}else{
declare += " where " + geometryColumn;
declare += " && setsrid('BOX3D(" + rect->asWKTCoords();
declare += ")'::box3d,";
declare += srid;
declare += ")";
}
if(sqlWhereClause.length() > 0)
{
declare += " and (" + sqlWhereClause + ")";
}
QgsDebugMsg("Selecting features using: " + declare);
// set up the cursor
if(ready){
PQexec(connection, "end work");
}
PQexec(connection,"begin work");
ready = true;
PQexec(connection, (const char *)(declare.utf8()));
// TODO - see if this deallocates member features
mFeatureQueue.empty();
}
QgsDataSourceURI * QgsPostgresProvider::getURI()
{
return &mUri;
}
/**
* Identify features within the search radius specified by rect
* @param rect Bounding rectangle of search radius
* @return std::vector containing QgsFeature objects that intersect rect
*/
std::vector<QgsFeature>& QgsPostgresProvider::identify(QgsRect * rect)
{
features.clear();
// select the features
select(rect);
return features;
}
/* unsigned char * QgsPostgresProvider::getGeometryPointer(OGRFeature *fet){
// OGRGeometry *geom = fet->GetGeometryRef();
unsigned char *gPtr=0;
// get the wkb representation
gPtr = new unsigned char[geom->WkbSize()];
geom->exportToWkb((OGRwkbByteOrder) endian(), gPtr);
return gPtr;
} */
void QgsPostgresProvider::setExtent( QgsRect* newExtent )
{
layerExtent.setXmax( newExtent->xMax() );
layerExtent.setXmin( newExtent->xMin() );
layerExtent.setYmax( newExtent->yMax() );
layerExtent.setYmin( newExtent->yMin() );
}
// TODO - make this function return the real extent_
QgsRect *QgsPostgresProvider::extent()
{
return &layerExtent; //extent_->MinX, extent_->MinY, extent_->MaxX, extent_->MaxY);
}
/**
* Return the feature type
*/
int QgsPostgresProvider::geometryType() const
{
return geomType;
}
/**
* Return the feature type
*/
long QgsPostgresProvider::featureCount() const
{
return numberFeatures;
}
/**
* Return the number of fields
*/
int QgsPostgresProvider::fieldCount() const
{
return attributeFields.size();
}
/**
* Fetch attributes for a selected feature
*/
void QgsPostgresProvider::getFeatureAttributes(int key, int &row, QgsFeature *f) {
QString sql = QString("select * from %1 where \"%2\" = %3").arg(mSchemaTableName).arg(primaryKey).arg(key);
QgsDebugMsg("QgsPostgresProvider::getFeatureAttributes using: " + sql);
PGresult *attr = PQexec(connection, (const char *)(sql.utf8()));
for (int i = 0; i < PQnfields(attr); i++) {
QString fld = PQfname(attr, i);
// Dont add the WKT representation of the geometry column to the identify
// results
if(fld != geometryColumn){
// Add the attribute to the feature
//QString val = mEncoding->toUnicode(PQgetvalue(attr,0, i));
QString val = QString::fromUtf8 (PQgetvalue(attr, row, i));
f->addAttribute(fld, val);
}
}
PQclear(attr);
}
/**Fetch attributes with indices contained in attlist*/
void QgsPostgresProvider::getFeatureAttributes(int key, int &row,
QgsFeature *f,
std::list<int> const & attlist)
{
std::list<int>::const_iterator iter;
for(iter=attlist.begin();iter!=attlist.end();++iter)
{
QString sql = QString("select \"%1\" from %2 where \"%3\" = %4")
.arg(fields()[*iter].name())
.arg(mSchemaTableName)
.arg(primaryKey)
.arg(key);//todo: only query one attribute
PGresult *attr = PQexec(connection, (const char *)(sql.utf8()));
QString fld = PQfname(attr, 0);
// Dont add the WKT representation of the geometry column to the identify
// results
if(fld != geometryColumn)
{
// Add the attribute to the feature
QString val = QString::fromUtf8(PQgetvalue(attr, 0, 0));
f->addAttribute(fld, val);
}
PQclear(attr);
}
}
void QgsPostgresProvider::getFeatureGeometry(int key, QgsFeature *f)
{
if (!valid)
{
return;
}
QString cursor = QString("declare qgisf binary cursor for "
"select asbinary(\"%1\",'%2') from %3 where \"%4\" = %5")
.arg(geometryColumn)
.arg(endianString())
.arg(mSchemaTableName)
.arg(primaryKey)
.arg(key);
QgsDebugMsg("QgsPostgresProvider::getFeatureGeometry using: " + cursor);
if (ready)
PQexec(connection, "end work");
PQexec(connection, "begin work");
ready = true;
PQexec(connection, (const char *)(cursor.utf8()));
QString fetch = "fetch forward 1 from qgisf";
PGresult *geomResult = PQexec(connection, (const char *)fetch);
if (PQntuples(geomResult) == 0)
{
// Nothing found - therefore nothing to change
PQexec(connection,"end work");
ready = false;
PQclear(geomResult);
return;
}
int row = 0;
int returnedLength = PQgetlength(geomResult, row, 0);
if(returnedLength > 0)
{
unsigned char *wkbgeom = new unsigned char[returnedLength];
memcpy(wkbgeom, PQgetvalue(geomResult, row, 0), returnedLength);
f->setGeometryAndOwnership(wkbgeom, returnedLength);
}
else
{
//QgsDebugMsg("Couldn't get the feature geometry in binary form");
}
PQclear(geomResult);
if (ready)
PQexec(connection,"end work");
ready = false;
}
std::vector<QgsField> const & QgsPostgresProvider::fields() const
{
return attributeFields;
}
void QgsPostgresProvider::reset()
{
// reset the cursor to the first record
//QgsDebugMsg("Resetting the cursor to the first record ");
QString declare = QString("declare qgisf binary cursor for select \"" +
primaryKey +
"\",asbinary(\"%1\",'%2') as qgs_feature_geometry from %3").arg(geometryColumn)
.arg(endianString()).arg(mSchemaTableName);
if(sqlWhereClause.length() > 0)
{
declare += " where " + sqlWhereClause;
}
//QgsDebugMsg("Selecting features using: " + declare);
QgsDebugMsg("Setting up binary cursor: " + declare);
// set up the cursor
if (ready)
PQexec(connection,"end work");
PQexec(connection,"begin work");
ready = true;
PQexec(connection, (const char *)(declare.utf8()));
//QgsDebugMsg("Error: " + PQerrorMessage(connection));
// TODO - see if this deallocates member features
mFeatureQueue.empty();
}
/* QString QgsPostgresProvider::getFieldTypeName(PGconn * pd, int oid)
{
QString typOid = QString().setNum(oid);
QString sql = "select typelem from pg_type where typelem = " + typOid + " and typlen = -1";
////QgsDebugMsg(sql);
PGresult *result = PQexec(pd, (const char *) sql);
// get the oid of the "real" type
QString poid = PQgetvalue(result, 0, PQfnumber(result, "typelem"));
PQclear(result);
sql = "select typname, typlen from pg_type where oid = " + poid;
// QgsDebugMsg(sql);
result = PQexec(pd, (const char *) sql);
QString typeName = PQgetvalue(result, 0, 0);
QString typeLen = PQgetvalue(result, 0, 1);
PQclear(result);
typeName += "(" + typeLen + ")";
return typeName;
} */
/** @todo XXX Perhaps this should be promoted to QgsDataProvider? */
QString QgsPostgresProvider::endianString()
{
switch ( endian() )
{
case QgsDataProvider::NDR :
return QString("NDR");
break;
case QgsDataProvider::XDR :
return QString("XDR");
break;
default :
return QString("UNKNOWN");
}
}
QString QgsPostgresProvider::getPrimaryKey()
{
// check to see if there is an unique index on the relation, which
// can be used as a key into the table. Primary keys are always
// unique indices, so we catch them as well.
QString sql = "select indkey from pg_index where indisunique = 't' and "
"indrelid = (select oid from pg_class where relname = '"
+ mTableName + "' and relnamespace = (select oid from pg_namespace where "
"nspname = '" + mSchemaName + "'))";
QgsDebugMsg("Getting unique index using '" + sql);;
PGresult *pk = executeDbCommand(connection, sql);
QgsDebugMsg("Got " + QString::number(PQntuples(pk)) + " rows");
QStringList log;
// if we got no tuples we ain't got no unique index :)
if (PQntuples(pk) == 0)
{
QgsDebugMsg("Relation has no unique index -- investigating alternatives");
// Two options here. If the relation is a table, see if there is
// an oid column that can be used instead.
// If the relation is a view try to find a suitable column to use as
// the primary key.
sql = "select relkind from pg_class where relname = '" + mTableName +
"' and relnamespace = (select oid from pg_namespace where "
"nspname = '" + mSchemaName + "')";
PGresult* tableType = executeDbCommand(connection, sql);
QString type = PQgetvalue(tableType, 0, 0);
PQclear(tableType);
primaryKey = "";
if (type == "r") // the relation is a table
{
QgsDebugMsg("Relation is a table. Checking to see if it has an oid column.");
// If there is an oid on the table, use that instead,
// otherwise give up
sql = "select attname from pg_attribute where attname = 'oid' and "
"attrelid = (select oid from pg_class where relname = '" +
mTableName + "' and relnamespace = (select oid from pg_namespace "
"where nspname = '" + mSchemaName + "'))";
PGresult* oidCheck = executeDbCommand(connection, sql);
if (PQntuples(oidCheck) != 0)
{
// Could warn the user here that performance will suffer if
// oid isn't indexed (and that they may want to add a
// primary key to the table)
primaryKey = "oid";
primaryKeyType = "int4";
}
else
{
showMessageBox(tr("No suitable key column in table"),
tr("The table has no column suitable for use as a key.\n\n"
"Qgis requires that the table either has a column of type\n"
"int4 with a unique constraint on it (which includes the\n"
"primary key) or has a PostgreSQL oid column.\n"));
}
PQclear(oidCheck);
}
else if (type == "v") // the relation is a view
{
// Have a poke around the view to see if any of the columns
// could be used as the primary key.
tableCols cols;
// Given a schema.view, populate the cols variable with the
// schema.table.column's that underly the view columns.
findColumns(cols);
// From the view columns, choose one for which the underlying
// column is suitable for use as a key into the view.
primaryKey = chooseViewColumn(cols);
}
else
qWarning("Unexpected relation type of '" + type + "'.");
}
else // have some unique indices on the table. Now choose one...
{
// choose which (if more than one) unique index to use
std::vector<std::pair<QString, QString> > suitableKeyColumns;
for (int i = 0; i < PQntuples(pk); ++i)
{
QString col = PQgetvalue(pk, i, 0);
QStringList columns = QStringList::split(" ", col);
if (columns.count() == 1)
{
// Get the column name and data type
sql = "select attname, pg_type.typname from pg_attribute, pg_type where "
"atttypid = pg_type.oid and attnum = " +
col + " and attrelid = (select oid from pg_class where " +
"relname = '" + mTableName + "' and relnamespace = (select oid "
"from pg_namespace where nspname = '" + mSchemaName + "'))";
PGresult* types = executeDbCommand(connection, sql);
assert(PQntuples(types) > 0); // should never happen
QString columnName = PQgetvalue(types, 0, 0);
QString columnType = PQgetvalue(types, 0, 1);
if (columnType != "int4")
log.append(tr("The unique index on column") +
" '" + columnName + "' " +
tr("is unsuitable because Qgis does not currently support"
" non-int4 type columns as a key into the table.\n"));
else
suitableKeyColumns.push_back(std::make_pair(columnName, columnType));
PQclear(types);
}
else
{
sql = "select attname from pg_attribute, pg_type where "
"atttypid = pg_type.oid and attnum in (" +
col.replace(" ", ",")
+ ") and attrelid = (select oid from pg_class where " +
"relname = '" + mTableName + "' and relnamespace = (select oid "
"from pg_namespace where nspname = '" + mSchemaName + "'))";
PGresult* types = executeDbCommand(connection, sql);
QString colNames;
int numCols = PQntuples(types);
for (int j = 0; j < numCols; ++j)
{
if (j == numCols-1)
colNames += tr("and ");
colNames += "'" + QString(PQgetvalue(types, j, 0))
+ (j < numCols-2 ? "', " : "' ");
}
log.append(tr("The unique index based on columns ") + colNames +
tr(" is unsuitable because Qgis does not currently support"
" multiple columns as a key into the table.\n"));
}
}
// suitableKeyColumns now contains the name of columns (and their
// data type) that
// are suitable for use as a key into the table. If there is
// more than one we need to choose one. For the moment, just
// choose the first in the list.
if (suitableKeyColumns.size() > 0)
{
primaryKey = suitableKeyColumns[0].first;
primaryKeyType = suitableKeyColumns[0].second;
}
else
{
// If there is an oid on the table, use that instead,
// otherwise give up
sql = "select attname from pg_attribute where attname = 'oid' and "
"attrelid = (select oid from pg_class where relname = '" +
mTableName + "' and relnamespace = (select oid from pg_namespace "
"where nspname = '" + mSchemaName + "'))";
PGresult* oidCheck = executeDbCommand(connection, sql);
if (PQntuples(oidCheck) != 0)
{
primaryKey = "oid";
primaryKeyType = "int4";
}
else
{
log.prepend("There were no columns in the table that were suitable "
"as a qgis key into the table (either a column with a "
"unique index and type int4 or a PostgreSQL oid column.\n");
}
PQclear(oidCheck);
}
// Either primaryKey has been set by the above code, or it
// hasn't. If not, present some info to the user to give them some
// idea of why not.
if (primaryKey.isEmpty())
{
// Give some info to the user about why things didn't work out.
valid = false;
showMessageBox(tr("Unable to find a key column"), log);
}
}
PQclear(pk);
#ifdef QGISDEBUG
if (primaryKey.length() > 0)
{
QgsDebugMsg("Qgis row key is " + primaryKey);
}
else
{
QgsDebugMsg("Qgis row key was not set.");
}
#endif
return primaryKey;
}
// Given the table and column that each column in the view refers to,
// choose one. Prefers column with an index on them, but will
// otherwise choose something suitable.
QString QgsPostgresProvider::chooseViewColumn(const tableCols& cols)
{
// For each relation name and column name need to see if it
// has unique constraints on it, or is a primary key (if not,
// it shouldn't be used). Should then be left with one or more
// entries in the map which can be used as the key.
QString sql, key;
QStringList log;
tableCols suitable;
// Cache of relation oid's
std::map<QString, QString> relOid;
std::vector<tableCols::const_iterator> oids;
tableCols::const_iterator iter = cols.begin();
for (; iter != cols.end(); ++iter)
{
QString viewCol = iter->first;
QString schemaName = iter->second.schema;
QString tableName = iter->second.relation;
QString tableCol = iter->second.column;
QString colType = iter->second.type;
// Get the oid from pg_class for the given schema.relation for use
// in subsequent queries.
sql = "select oid from pg_class where relname = '" + tableName +
"' and relnamespace = (select oid from pg_namespace where "
" nspname = '" + schemaName + "')";
PGresult* result = PQexec(connection, (const char*)(sql.utf8()));
QString rel_oid;
if (PQntuples(result) == 1)
{
rel_oid = PQgetvalue(result, 0, 0);
// Keep the rel_oid for use later one.
relOid[viewCol] = rel_oid;
}
else
{
QgsDebugMsg("Relation " + schemaName + "." + tableName + " doesn't exist in the pg_class table. This shouldn't happen and is odd.");
assert(0);
}
PQclear(result);
// This sql returns one or more rows if the column 'tableCol' in
// table 'tableName' and schema 'schemaName' has one or more
// columns that satisfy the following conditions:
// 1) the column has data type of int4.
// 2) the column has a unique constraint or primary key constraint
// on it.
// 3) the constraint applies just to the column of interest (i.e.,
// it isn't a constraint over multiple columns.
sql = "select * from pg_constraint where conkey[1] = "
"(select attnum from pg_attribute where attname = '" + tableCol + "' "
"and attrelid = " + rel_oid + ")"
"and conrelid = " + rel_oid + " "
"and (contype = 'p' or contype = 'u') "
"and array_dims(conkey) = '[1:1]'";
result = PQexec(connection, (const char*)(sql.utf8()));
if (PQntuples(result) == 1 && colType == "int4")
suitable[viewCol] = iter->second;
QString details = "'" + viewCol + "'" + tr(" derives from ")
+ "'" + schemaName + "." + tableName + "." + tableCol + "' ";
if (PQntuples(result) == 1 && colType == "int4")
{
details += tr("and is suitable.");
}
else
{
details += tr("and is not suitable ");
details += "(" + tr("type is ") + colType;
if (PQntuples(result) == 1)
details += tr(" and has a suitable constraint)");
else
details += tr(" and does not have a suitable constraint)");
}
log << details;
PQclear(result);
if (tableCol == "oid")
oids.push_back(iter);
}
// 'oid' columns in tables don't have a constraint on them, but
// they are useful to consider, so add them in if not already
// here.
for (int i = 0; i < oids.size(); ++i)
{
if (suitable.find(oids[i]->first) == suitable.end())
{
suitable[oids[i]->first] = oids[i]->second;
QgsDebugMsg("Adding column " + oids[i]->first + " as it may be suitable.");
}
}
// Now have a map containing all of the columns in the view that
// might be suitable for use as the key to the table. Need to choose
// one thus:
//
// If there is more than one suitable column pick one that is
// indexed, else pick one called 'oid' if it exists, else
// pick the first one. If there are none we return an empty string.
// Search for one with an index
tableCols::const_iterator i = suitable.begin();
for (; i != suitable.end(); ++i)
{
// Get the relation oid from our cache.
QString rel_oid = relOid[i->first];
// And see if the column has an index
sql = "select * from pg_index where indrelid = " + rel_oid +
" and indkey[0] = (select attnum from pg_attribute where "
"attrelid = " + rel_oid + " and attname = '" + i->second.column + "')";
PGresult* result = PQexec(connection, (const char*)(sql.utf8()));
if (PQntuples(result) > 0 && uniqueData(mSchemaName, mTableName, i->first))
{ // Got one. Use it.
key = i->first;
QgsDebugMsg("Picked column '" + key + "' because it has an index.");
break;
}
PQclear(result);
}
if (key.isEmpty())
{
// If none have indices, choose one that is called 'oid' (if it
// exists). This is legacy support and could be removed in
// future.
i = suitable.find("oid");
if (i != suitable.end() && uniqueData(mSchemaName, mTableName, i->first))
{
key = i->first;
QgsDebugMsg("Picked column " + key + " as it is probably the postgresql object id column (which contains unique values) and there are no columns with indices to choose from");
}
// else choose the first one in the container that has unique data
else
{
tableCols::const_iterator i = suitable.begin();
for (; i != suitable.end(); ++i)
{
if (uniqueData(mSchemaName, mTableName, i->first))
{
key = i->first;
QgsDebugMsg("Picked column " + key + " as it was the first suitable column found with unique data and were are no columns with indices to choose from.");
break;
}
else
{
log << QString(tr("Note: ") + "'" + i->first + "' "
+ tr("initially appeared suitable but does not "
"contain unique data, so is not suitable.\n"));
}
}
}
}
if (key.isEmpty())
{
valid = false;
// Successive prepends means that the text appears in the dialog
// box in the reverse order to that seen here.
log.prepend(tr("The view you selected has the following columns, none "
"of which satisfy the above conditions:"));
log.prepend(tr("Qgis requires that the view has a column that can be used "
"as a unique key. Such a column should be derived from "
"a table column of type int4 and be a primary key, "
"have a unique constraint on it, or be a PostgreSQL "
"oid column. To improve "
"performance the column should also be indexed.\n"));
log.prepend(tr("The view ") + "'" + mSchemaName + '.' + mTableName + "' " +
tr("has no column suitable for use as a unique key.\n"));
showMessageBox(tr("No suitable key column in view"), log);
}
return key;
}
bool QgsPostgresProvider::uniqueData(QString schemaName,
QString tableName, QString colName)
{
// Check to see if the given column contains unique data
bool isUnique = false;
QString sql = "select count(distinct \"" + colName + "\") = count(\"" +
colName + "\") from \"" + schemaName + "\".\"" + tableName + "\"";
PGresult* unique = PQexec(connection, (const char*) (sql.utf8()));
if (PQntuples(unique) == 1)
if (strncmp(PQgetvalue(unique, 0, 0),"t", 1) == 0)
isUnique = true;
PQclear(unique);
return isUnique;
}
// This function will return in the cols variable the
// underlying view and columns for each column in
// mSchemaName.mTableName.
void QgsPostgresProvider::findColumns(tableCols& cols)
{
// This sql is derived from the one that defines the view
// 'information_schema.view_column_usage' in PostgreSQL, with a few
// mods to suit our purposes.
QString sql = ""
"SELECT DISTINCT "
" nv.nspname AS view_schema, "
" v.relname AS view_name, "
" a.attname AS view_column_name, "
" nt.nspname AS table_schema, "
" t.relname AS table_name, "
" a.attname AS column_name, "
" t.relkind as table_type, "
" typ.typname as column_type "
"FROM "
" pg_namespace nv, "
" pg_class v, "
" pg_depend dv,"
" pg_depend dt, "
" pg_class t, "
" pg_namespace nt, "
" pg_attribute a,"
" pg_user u, "
" pg_type typ "
"WHERE "
" nv.oid = v.relnamespace AND "
" v.relkind = 'v'::\"char\" AND "
" v.oid = dv.refobjid AND "
" dv.refclassid = 'pg_class'::regclass::oid AND "
" dv.classid = 'pg_rewrite'::regclass::oid AND "
" dv.deptype = 'i'::\"char\" AND "
" dv.objid = dt.objid AND "
" dv.refobjid <> dt.refobjid AND "
" dt.classid = 'pg_rewrite'::regclass::oid AND "
" dt.refclassid = 'pg_class'::regclass::oid AND "
" dt.refobjid = t.oid AND "
" t.relnamespace = nt.oid AND "
" (t.relkind = 'r'::\"char\" OR t.relkind = 'v'::\"char\") AND "
" t.oid = a.attrelid AND "
" dt.refobjsubid = a.attnum AND "
" nv.nspname NOT IN ('pg_catalog', 'information_schema' ) AND "
" a.atttypid = typ.oid";
// A structure to store the results of the above sql.
typedef std::map<QString, TT> columnRelationsType;
columnRelationsType columnRelations;
// A structure to cache the query results that return the view
// definition.
typedef QMap<QString, QString> viewDefCache;
viewDefCache viewDefs;
PGresult* result = PQexec(connection, (const char*)(sql.utf8()));
// Store the results of the query for convenient access
for (int i = 0; i < PQntuples(result); ++i)
{
TT temp;
temp.view_schema = PQgetvalue(result, i, 0);
temp.view_name = PQgetvalue(result, i, 1);
temp.view_column_name = PQgetvalue(result, i, 2);
temp.table_schema = PQgetvalue(result, i, 3);
temp.table_name = PQgetvalue(result, i, 4);
temp.column_name = PQgetvalue(result, i, 5);
temp.table_type = PQgetvalue(result, i, 6);
temp.column_type = PQgetvalue(result, i, 7);
// BUT, the above SQL doesn't always give the correct value for the view
// column name (that's because that information isn't available directly
// from the database), mainly when the view column name has been renamed
// using 'AS'. To fix this we need to look in the view definition and
// adjust the view column name if necessary.
QString viewQuery = "SELECT definition FROM pg_views "
"WHERE schemaname = '" + temp.view_schema + "' AND "
"viewname = '" + temp.view_name + "'";
// Maintain a cache of the above SQL.
QString viewDef;
if (!viewDefs.contains(viewQuery))
{
PGresult* r = PQexec(connection, (const char*)(viewQuery.utf8()));
if (PQntuples(r) > 0)
viewDef = PQgetvalue(r, 0, 0);
else
QgsDebugMsg("Failed to get view definition for " + temp.view_schema + "." + temp.view_name);
viewDefs[viewQuery] = viewDef;
}
viewDef = viewDefs.value(viewQuery);
// Now pick the view definiton apart, looking for
// temp.column_name to the left of an 'AS'.
// This regular expression needs more testing. Since the view
// definition comes from postgresql and has been 'standardised', we
// don't need to deal with everything that the user could put in a view
// definition. Does the regexp have to deal with the schema??
if (!viewDef.isEmpty())
{
QRegExp s(".* \"?" + QRegExp::escape(temp.table_name) +
"\"?\\.\"?" + QRegExp::escape(temp.column_name) +
"\"? AS \"?(\\w+)\"?,* .*");
#ifdef QGSIDEBUG
std::cerr <<__FILE__<<__LINE__ << ' ' << viewQuery.toLocal8Bit().data() << '\n'
<< viewDef.toLocal8Bit().data() << '\n'
<< s.pattern().toLocal8Bit().data() << '\n';
#endif
if (s.indexIn(viewDef) != -1)
{
temp.view_column_name = s.cap(1);
//std::cerr<<__FILE__<<__LINE__<<' '<<temp.view_column_name.toLocal8Bit().data()<<'\n';
}
}
QgsDebugMsg(temp.view_schema + "."
+ temp.view_name + "."
+ temp.view_column_name + " <- "
+ temp.table_schema + "."
+ temp.table_name + "."
+ temp.column_name + " is a '"
+ temp.table_type + "' of type "
+ temp.column_type);
columnRelations[temp.view_schema + '.' +
temp.view_name + '.' +
temp.view_column_name] = temp;
}
PQclear(result);
// Loop over all columns in the view in question.
sql = "SELECT pg_namespace.nspname || '.' || "
"pg_class.relname || '.' || pg_attribute.attname "
"FROM pg_attribute, pg_class, pg_namespace "
"WHERE pg_class.relname = '" + mTableName + "' "
"AND pg_namespace.nspname = '" + mSchemaName + "' "
"AND pg_attribute.attrelid = pg_class.oid "
"AND pg_class.relnamespace = pg_namespace.oid";
result = PQexec(connection, (const char*)(sql.utf8()));
// Loop over the columns in mSchemaName.mTableName and find out the
// underlying schema, table, and column name.
for (int i = 0; i < PQntuples(result); ++i)
{
columnRelationsType::const_iterator
ii = columnRelations.find(PQgetvalue(result, i, 0));
columnRelationsType::const_iterator start_iter = ii;
if (ii == columnRelations.end())
continue;
int count = 0;
const int max_loops = 100;
while (ii->second.table_type != "r" && count < max_loops)
{
QgsDebugMsg("Searching for the column that " + ii->second.table_schema + "."
+ ii->second.table_name + "." + ii->second.column_name + " refers to.");
columnRelationsType::const_iterator
jj = columnRelations.find(QString(ii->second.table_schema + '.' +
ii->second.table_name + '.' +
ii->second.column_name));
if (jj == columnRelations.end())
{
QgsDebugMsg("WARNING: Failed to find the column that " + ii->second.table_schema + "."
+ ii->second.table_name + "." + ii->second.column_name + " refers to.");
break;
}
ii = jj;
++count;
}
if (count >= max_loops)
{
QgsDebugMsg(" Search for the underlying table.column for view column "
+ ii->second.table_schema + "."
+ ii->second.table_name + "."
+ ii->second.column_name + " failed: exceeded maximum "
+ "interation limit (" + QString::number(max_loops) + ").");
cols[ii->second.view_column_name] = SRC("","","","");
}
else if (ii != columnRelations.end())
{
cols[start_iter->second.view_column_name] =
SRC(ii->second.table_schema,
ii->second.table_name,
ii->second.column_name,
ii->second.column_type);
QgsDebugMsg(QString(PQgetvalue(result, i, 0)) + QString(" derives from ") + QString(ii->second.table_schema) + "."
+ ii->second.table_name + "." + ii->second.column_name);
}
}
PQclear(result);
}
// Returns the minimum value of an attribute
QString QgsPostgresProvider::minValue(int position){
// get the field name
QgsField fld = attributeFields[position];
QString sql;
if(sqlWhereClause.isEmpty())
{
sql = QString("select min(\"%1\") from %2").arg(fld.name()).arg(mSchemaTableName);
}
else
{
sql = QString("select min(\"%1\") from %2").arg(fld.name()).arg(mSchemaTableName)+" where "+sqlWhereClause;
}
PGresult *rmin = PQexec(connection,(const char *)(sql.utf8()));
QString minValue = PQgetvalue(rmin,0,0);
PQclear(rmin);
return minValue;
}
// Returns the maximum value of an attribute
QString QgsPostgresProvider::maxValue(int position){
// get the field name
QgsField fld = attributeFields[position];
QString sql;
if(sqlWhereClause.isEmpty())
{
sql = QString("select max(\"%1\") from %2").arg(fld.name()).arg(mSchemaTableName);
}
else
{
sql = QString("select max(\"%1\") from %2").arg(fld.name()).arg(mSchemaTableName)+" where "+sqlWhereClause;
}
PGresult *rmax = PQexec(connection,(const char *)(sql.utf8()));
QString maxValue = PQgetvalue(rmax,0,0);
PQclear(rmax);
return maxValue;
}
int QgsPostgresProvider::maxPrimaryKeyValue()
{
QString sql;
sql = QString("select max(\"%1\") from %2")
.arg(primaryKey)
.arg(mSchemaTableName);
PGresult *rmax = PQexec(connection,(const char *)(sql.utf8()));
QString maxValue = PQgetvalue(rmax,0,0);
PQclear(rmax);
return maxValue.toInt();
}
bool QgsPostgresProvider::isValid(){
return valid;
}
bool QgsPostgresProvider::addFeature(QgsFeature* f, int primaryKeyHighWater)
{
QgsDebugMsg("QgsPostgresProvider::addFeature: Entering.");
if (f)
{
// Determine which insertion method to use for WKB
// PostGIS 1.0+ uses BYTEA
// earlier versions use HEX
bool useWkbHex(FALSE);
if (!gotPostgisVersion)
{
postgisVersion(connection);
}
QgsDebugMsg("QgsPostgresProvider::addFeature: PostGIS version is major: " + QString::number(postgisVersionMajor) + ", minor: " + QString::number(postgisVersionMinor) + ".");
if (postgisVersionMajor < 1)
{
useWkbHex = TRUE;
}
// Start building insert string
QString insert("INSERT INTO ");
insert+=mSchemaTableName;
insert+=" (";
// add the name of the geometry column to the insert statement
insert += "\"" + geometryColumn;
// add the name of the primary key column to the insert statement
insert += "\",\"";
insert += primaryKey + "\"";
QgsDebugMsg("QgsPostgresProvider::addFeature: Constructing insert SQL, currently at: " + insert);
//add the names of the other fields to the insert
std::vector<QgsFeatureAttribute> attributevec=f->attributeMap();
QgsDebugMsg("QgsPostgresProvider::addFeature: Got attribute map.");
for(std::vector<QgsFeatureAttribute>::iterator it=attributevec.begin();it!=attributevec.end();++it)
{
QString fieldname=it->fieldName();
QgsDebugMsg("QgsPostgresProvider::addFeature: Checking field against: " + fieldname + ".");
//TODO: Check if field exists in this layer
// (Sometimes features will have fields that are not part of this layer since
// they have been pasted from other layers with a different field map)
bool fieldInLayer = FALSE;
for (std::vector<QgsField>::iterator iter = attributeFields.begin();
iter != attributeFields.end();
++iter)
{
if ( iter->name() == it->fieldName() )
{
fieldInLayer = TRUE;
break;
}
}
if (
(fieldname != geometryColumn) &&
(fieldname != primaryKey) &&
(!(it->fieldValue().isEmpty())) &&
(fieldInLayer)
)
{
insert+=",\"";
insert+=fieldname +"\"";
}
}
insert+=") VALUES (GeomFromWKB('";
// Add the WKB geometry to the INSERT statement
unsigned char* geom = f->getGeometry();
for (int i=0; i < f->getGeometrySize(); ++i)
{
if (useWkbHex)
{
// PostGIS < 1.0 wants hex
QString hex = QString::number((int) geom[i], 16).upper();
if (hex.length() == 1)
{
hex = "0" + hex;
}
insert += hex;
}
else
{
// Postgis 1.0 wants bytea
QString oct = QString::number((int) geom[i], 8);
if(oct.length()==3)
{
oct="\\\\"+oct;
}
else if(oct.length()==1)
{
oct="\\\\00"+oct;
}
else if(oct.length()==2)
{
oct="\\\\0"+oct;
}
insert += oct;
}
}
if (useWkbHex)
{
insert += "',"+srid+")";
}
else
{
insert += "::bytea',"+srid+")";
}
//add the primary key value to the insert statement
insert += ",";
insert += QString::number(primaryKeyHighWater);
//add the field values to the insert statement
for(std::vector<QgsFeatureAttribute>::iterator it=attributevec.begin();it!=attributevec.end();++it)
{
QString fieldname=it->fieldName();
QgsDebugMsg("QgsPostgresProvider::addFeature: Checking field name " + fieldname);
//TODO: Check if field exists in this layer
// (Sometimes features will have fields that are not part of this layer since
// they have been pasted from other layers with a different field map)
bool fieldInLayer = FALSE;
for (std::vector<QgsField>::iterator iter = attributeFields.begin();
iter != attributeFields.end();
++iter)
{
if ( iter->name() == it->fieldName() )
{
fieldInLayer = TRUE;
break;
}
}
if (
(fieldname != geometryColumn) &&
(fieldname != primaryKey) &&
(!(it->fieldValue().isEmpty())) &&
(fieldInLayer)
)
{
QString fieldvalue = it->fieldValue();
bool charactertype=false;
insert+=",";
QgsDebugMsg("QgsPostgresProvider::addFeature: Field is in layer with value " + fieldvalue);
//add quotes if the field is a character or date type and not
//the postgres provided default value
if(fieldvalue != "NULL" && fieldvalue != getDefaultValue(it->fieldName(), f))
{
for(std::vector<QgsField>::iterator iter=attributeFields.begin();iter!=attributeFields.end();++iter)
{
if(iter->name()==it->fieldName())
{
if (
iter->type().contains("char",false) > 0 ||
iter->type() == "text" ||
iter->type() == "date" ||
iter->type() == "interval" ||
iter->type().contains("time",false) > 0 // includes time and timestamp
)
{
charactertype=true;
break; // no need to continue with this loop
}
}
}
}
if(charactertype)
{
insert+="'";
}
// important: escape quotes in field value
fieldvalue.replace("'", "''");
insert+=fieldvalue;
if(charactertype)
{
insert+="'";
}
}
}
insert+=")";
QgsDebugMsg("insert statement is: " +insert);
//send INSERT statement and do error handling
PGresult* result=PQexec(connection, (const char *)(insert.utf8()));
if(result==0)
{
QMessageBox::information(0,tr("INSERT error"),tr("An error occured during feature insertion"),QMessageBox::Ok);
return false;
}
ExecStatusType message=PQresultStatus(result);
if(message==PGRES_FATAL_ERROR)
{
// Use QgsMessage viewer here instead of a QMessageBox because
// we want to include the offending SQL, which may be quite
// long, and the QMessageBox doesn't wrap text, etc.
QString sqlDetails = PQresultErrorMessage(result);
sqlDetails += tr("The sql was:\n\n") + insert;
QgsMessageViewer viewer;
viewer.setWindowTitle(tr("SQL error"));
viewer.setMessageAsPlainText(sqlDetails);
viewer.exec();
// QMessageBox::information(0,tr("INSERT error"), sqlDetails,QMessageBox::Ok);
return false;
}
QgsDebugMsg("QgsPostgresProvider::addFeature: Exiting with true.");
return true;
}
QgsDebugMsg("QgsPostgresProvider::addFeature: Exiting with false.");
return false;
}
QString QgsPostgresProvider::getDefaultValue(const QString& attr, QgsFeature* f)
{
// Get the default column value from the Postgres information
// schema. If there is no default we return an empty string.
// Maintaining a cache of the results of this query would be quite
// simple and if this query is called lots, could save some time.
QString sql("SELECT column_default FROM "
"information_schema.columns WHERE "
"column_default IS NOT NULL AND "
"table_schema = '" + mSchemaName + "' AND "
"table_name = '" + mTableName + "' AND "
"column_name = '" + attr + "'");
QString defaultValue("");
PGresult* result = PQexec(connection, (const char*)(sql.utf8()));
if (PQntuples(result) == 1)
defaultValue = PQgetvalue(result, 0, 0);
PQclear(result);
return defaultValue;
}
bool QgsPostgresProvider::deleteFeature(int id)
{
QString sql("DELETE FROM "+mSchemaTableName+" WHERE \""+primaryKey+"\" = "+QString::number(id));
QgsDebugMsg("delete sql: " + sql);
//send DELETE statement and do error handling
PGresult* result=PQexec(connection, (const char *)(sql.utf8()));
if(result==0)
{
QMessageBox::information(0,tr("DELETE error"),tr("An error occured during deletion from disk"),QMessageBox::Ok);
return false;
}
ExecStatusType message=PQresultStatus(result);
if(message==PGRES_FATAL_ERROR)
{
QMessageBox::information(0,tr("DELETE error"),QString(PQresultErrorMessage(result)),QMessageBox::Ok);
return false;
}
return true;
}
/**
* Check to see if GEOS is available
*/
bool QgsPostgresProvider::hasGEOS(PGconn *connection){
// make sure info is up to date for the current connection
postgisVersion(connection);
// get geos capability
return geosAvailable;
}
/* Functions for determining available features in postGIS */
QString QgsPostgresProvider::postgisVersion(PGconn *connection)
{
PGresult *result = PQexec(connection, "select postgis_version()");
postgisVersionInfo = PQgetvalue(result,0,0);
QgsDebugMsg("PostGIS version info: " + postgisVersionInfo);
PQclear(result);
QStringList postgisParts = QStringList::split(" ", postgisVersionInfo);
// Get major and minor version
QStringList postgisVersionParts = QStringList::split(".", postgisParts[0]);
postgisVersionMajor = postgisVersionParts[0].toInt();
postgisVersionMinor = postgisVersionParts[1].toInt();
// assume no capabilities
geosAvailable = false;
gistAvailable = false;
projAvailable = false;
// parse out the capabilities and store them
QStringList geos = postgisParts.grep("GEOS");
if(geos.size() == 1){
geosAvailable = (geos[0].find("=1") > -1);
}
QStringList gist = postgisParts.grep("STATS");
if(gist.size() == 1){
gistAvailable = (geos[0].find("=1") > -1);
}
QStringList proj = postgisParts.grep("PROJ");
if(proj.size() == 1){
projAvailable = (proj[0].find("=1") > -1);
}
gotPostgisVersion = TRUE;
return postgisVersionInfo;
}
bool QgsPostgresProvider::addFeatures(std::list<QgsFeature*> const flist)
{
bool returnvalue=true;
PQexec(connection,"BEGIN");
int primaryKeyHighWater = maxPrimaryKeyValue();
for(std::list<QgsFeature*>::const_iterator it=flist.begin();it!=flist.end();++it)
{
primaryKeyHighWater++;
if(!addFeature(*it, primaryKeyHighWater))
{
returnvalue=false;
// TODO: exit loop here?
}
}
PQexec(connection,"COMMIT");
reset();
return returnvalue;
}
bool QgsPostgresProvider::deleteFeatures(std::list<int> const & id)
{
bool returnvalue=true;
PQexec(connection,"BEGIN");
for(std::list<int>::const_iterator it=id.begin();it!=id.end();++it)
{
if(!deleteFeature(*it))
{
returnvalue=false;
}
}
PQexec(connection,"COMMIT");
reset();
return returnvalue;
}
bool QgsPostgresProvider::addAttributes(std::map<QString,QString> const & name)
{
bool returnvalue=true;
PQexec(connection,"BEGIN");
for(std::map<QString,QString>::const_iterator iter=name.begin();iter!=name.end();++iter)
{
QString sql="ALTER TABLE "+mSchemaTableName+" ADD COLUMN "+(*iter).first+" "+(*iter).second;
QgsDebugMsg(sql);
//send sql statement and do error handling
PGresult* result=PQexec(connection, (const char *)(sql.utf8()));
if(result==0)
{
returnvalue=false;
ExecStatusType message=PQresultStatus(result);
if(message==PGRES_FATAL_ERROR)
{
QMessageBox::information(0,"ALTER TABLE error",QString(PQresultErrorMessage(result)),QMessageBox::Ok);
}
}
}
PQexec(connection,"COMMIT");
reset();
return returnvalue;
}
bool QgsPostgresProvider::deleteAttributes(std::set<QString> const & name)
{
bool returnvalue=true;
PQexec(connection,"BEGIN");
for(std::set<QString>::const_iterator iter=name.begin();iter!=name.end();++iter)
{
QString sql="ALTER TABLE "+mSchemaTableName+" DROP COLUMN "+(*iter);
QgsDebugMsg(sql);
//send sql statement and do error handling
PGresult* result=PQexec(connection, (const char *)(sql.utf8()));
if(result==0)
{
returnvalue=false;
ExecStatusType message=PQresultStatus(result);
if(message==PGRES_FATAL_ERROR)
{
QMessageBox::information(0,"ALTER TABLE error",QString(PQresultErrorMessage(result)),QMessageBox::Ok);
}
}
else
{
//delete the attribute from attributeFields
for(std::vector<QgsField>::iterator it=attributeFields.begin();it!=attributeFields.end();++it)
{
if((*it).name()==(*iter))
{
attributeFields.erase(it);
break;
}
}
}
}
PQexec(connection,"COMMIT");
reset();
return returnvalue;
}
bool QgsPostgresProvider::changeAttributeValues(std::map<int,std::map<QString,QString> > const & attr_map)
{
bool returnvalue=true;
PQexec(connection,"BEGIN");
for(std::map<int,std::map<QString,QString> >::const_iterator iter=attr_map.begin();iter!=attr_map.end();++iter)
{
for(std::map<QString,QString>::const_iterator siter=(*iter).second.begin();siter!=(*iter).second.end();++siter)
{
QString val = (*siter).second;
// escape quotes
val.replace("'", "''");
QString sql="UPDATE "+mSchemaTableName+" SET "+(*siter).first+"='"+val+"' WHERE \"" +primaryKey+"\"="+QString::number((*iter).first);
QgsDebugMsg(sql);
// s end sql statement and do error handling
// TODO: Make all error handling like this one
PGresult* result=PQexec(connection, (const char *)(sql.utf8()));
if (result==0)
{
QMessageBox::critical(0, tr("PostGIS error"),
tr("An error occured contacting the PostgreSQL databse"),
QMessageBox::Ok,
Qt::NoButton);
return false;
}
ExecStatusType message=PQresultStatus(result);
if(message==PGRES_FATAL_ERROR)
{
QMessageBox::information(0, tr("PostGIS error"),
tr("The PostgreSQL databse returned: ")
+ QString(PQresultErrorMessage(result))
+ "\n"
+ tr("When trying: ")
+ sql,
QMessageBox::Ok,
Qt::NoButton);
return false;
}
}
}
PQexec(connection,"COMMIT");
reset();
return returnvalue;
}
bool QgsPostgresProvider::changeGeometryValues(std::map<int, QgsGeometry> & geometry_map)
{
QgsDebugMsg("QgsPostgresProvider::changeGeometryValues: entering.");
bool returnvalue = true;
// Determine which insertion method to use for WKB
// PostGIS 1.0+ uses BYTEA
// earlier versions use HEX
bool useWkbHex(FALSE);
if (!gotPostgisVersion)
{
postgisVersion(connection);
}
QgsDebugMsg("QgsPostgresProvider::addFeature: PostGIS version is major: " + QString::number(postgisVersionMajor) + ", minor: " + QString::number(postgisVersionMinor) + ".");
if (postgisVersionMajor < 1)
{
useWkbHex = TRUE;
}
// Start the PostGIS transaction
PQexec(connection,"BEGIN");
for(std::map<int, QgsGeometry>::const_iterator iter = geometry_map.begin();
iter != geometry_map.end();
++iter)
{
QgsDebugMsg("QgsPostgresProvider::changeGeometryValues: iterating over the map of changed geometries...");
if (iter->second.wkbBuffer())
{
QgsDebugMsg("QgsPostgresProvider::changeGeometryValues: iterating over feature id " + iter->first);
QString sql = "UPDATE "+ mSchemaTableName +" SET \"" +
geometryColumn + "\"=";
sql += "GeomFromWKB('";
// Add the WKB geometry to the UPDATE statement
unsigned char* geom = iter->second.wkbBuffer();
for (int i=0; i < iter->second.wkbSize(); ++i)
{
if (useWkbHex)
{
// PostGIS < 1.0 wants hex
QString hex = QString::number((int) geom[i], 16).upper();
if (hex.length() == 1)
{
hex = "0" + hex;
}
sql += hex;
}
else
{
// Postgis 1.0 wants bytea
QString oct = QString::number((int) geom[i], 8);
if(oct.length()==3)
{
oct="\\\\"+oct;
}
else if(oct.length()==1)
{
oct="\\\\00"+oct;
}
else if(oct.length()==2)
{
oct="\\\\0"+oct;
}
sql += oct;
}
}
if (useWkbHex)
{
sql += "',"+srid+")";
}
else
{
sql += "::bytea',"+srid+")";
}
sql += " WHERE \"" +primaryKey+"\"="+QString::number(iter->first);
QgsDebugMsg("QgsPostgresProvider::changeGeometryValues: Updating with '" + sql + "'.");
// send sql statement and do error handling
// TODO: Make all error handling like this one
PGresult* result=PQexec(connection, (const char *)(sql.utf8()));
if (result==0)
{
QMessageBox::critical(0, tr("PostGIS error"),
tr("An error occured contacting the PostgreSQL databse"),
QMessageBox::Ok,
Qt::NoButton);
return false;
}
ExecStatusType message=PQresultStatus(result);
if(message==PGRES_FATAL_ERROR)
{
QMessageBox::information(0, tr("PostGIS error"),
tr("The PostgreSQL databse returned: ")
+ QString(PQresultErrorMessage(result))
+ "\n"
+ tr("When trying: ")
+ sql,
QMessageBox::Ok,
Qt::NoButton);
return false;
}
} // if (*iter)
/*
if(f)
{
QString insert("INSERT INTO \"");
insert+=tableName;
insert+="\" (";
//add the name of the geometry column to the insert statement
insert+=geometryColumn;//first the geometry
//add the names of the other fields to the insert
std::vector<QgsFeatureAttribute> attributevec=f->attributeMap();
for(std::vector<QgsFeatureAttribute>::iterator it=attributevec.begin();it!=attributevec.end();++it)
{
QString fieldname=it->fieldName();
if(fieldname!=geometryColumn)
{
insert+=",";
insert+=fieldname;
}
}
insert+=") VALUES (GeomFromWKB('";
//add the wkb geometry to the insert statement
unsigned char* geom=f->getGeometry();
for(int i=0;i<f->getGeometrySize();++i)
{
QString hex=QString::number((int)geom[i],16).upper();
if(hex.length()==1)
{
hex="0"+hex;
}
insert+=hex;
}
insert+="',"+srid+")";
//add the field values to the insert statement
for(std::vector<QgsFeatureAttribute>::iterator it=attributevec.begin();it!=attributevec.end();++it)
{
if(it->fieldName()!=geometryColumn)
{
QString fieldvalue=it->fieldValue();
bool charactertype=false;
insert+=",";
//add quotes if the field is a characted type
if(fieldvalue!="NULL")
{
for(std::vector<QgsField>::iterator iter=attributeFields.begin();iter!=attributeFields.end();++iter)
{
if(iter->name()==it->fieldName())
{
if(iter->type().contains("char",false)>0||iter->type()=="text")
{
charactertype=true;
}
}
}
}
if(charactertype)
{
insert+="'";
}
insert+=fieldvalue;
if(charactertype)
{
insert+="'";
}
}
}
insert+=")";
QgsDebugMsg("insert statement is: "+insert);
//send INSERT statement and do error handling
PGresult* result=PQexec(connection, (const char *)(insert.utf8()));
if(result==0)
{
QMessageBox::information(0,"INSERT error","An error occured during feature insertion",QMessageBox::Ok);
return false;
}
ExecStatusType message=PQresultStatus(result);
if(message==PGRES_FATAL_ERROR)
{
QMessageBox::information(0,"INSERT error",QString(PQresultErrorMessage(result)),QMessageBox::Ok);
return false;
}
return true;
}
return false;
for(std::map<QString,QString>::const_iterator siter=(*iter).second.begin();siter!=(*iter).second.end();++siter)
{
QString value=(*siter).second;
//find out, if value contains letters and quote if yes
bool text=false;
for(int i=0;i<value.length();++i)
{
if(value[i].isLetter())
{
text=true;
}
}
if(text)
{
value.prepend("'");
value.append("'");
}
QString sql="UPDATE \""+tableName+"\" SET "+(*siter).first+"="+value+" WHERE " +primaryKey+"="+QString::number((*iter).first);
QgsDebugMsg(sql);
//send sql statement and do error handling
PGresult* result=PQexec(connection, (const char *)(sql.utf8()));
if(result==0)
{
returnvalue=false;
ExecStatusType message=PQresultStatus(result);
if(message==PGRES_FATAL_ERROR)
{
QMessageBox::information(0,"UPDATE error",QString(PQresultErrorMessage(result)),QMessageBox::Ok);
}
}
}
}
*/
} // for each feature
PQexec(connection,"COMMIT");
// TODO: Reset Geometry dirty if commit was OK
reset();
QgsDebugMsg("QgsPostgresProvider::changeGeometryValues: exiting.");
return returnvalue;
}
bool QgsPostgresProvider::supportsSaveAsShapefile() const
{
return false;
}
int QgsPostgresProvider::capabilities() const
{
return (
QgsVectorDataProvider::AddFeatures |
QgsVectorDataProvider::DeleteFeatures |
QgsVectorDataProvider::ChangeAttributeValues |
QgsVectorDataProvider::AddAttributes |
QgsVectorDataProvider::DeleteAttributes |
QgsVectorDataProvider::ChangeGeometries |
QgsVectorDataProvider::SelectGeometryAtId
);
}
void QgsPostgresProvider::setSubsetString(QString theSQL)
{
sqlWhereClause=theSQL;
// Update datasource uri too
mUri.sql=theSQL;
// Update yet another copy of the uri. Why are there 3 copies of the
// uri? Perhaps this needs some rationalisation.....
setDataSourceUri(mUri.text());
// need to recalculate the number of features...
getFeatureCount();
calculateExtents();
}
long QgsPostgresProvider::getFeatureCount()
{
// get total number of features
// First get an approximate count; then delegate to
// a thread the task of getting the full count.
#ifdef POSTGRESQL_THREADS
QString sql = "select reltuples from pg_catalog.pg_class where relname = '" +
tableName + "'";
QgsDebugMsg("QgsPostgresProvider: Running SQL: " + sql);
#else
QString sql = "select count(*) from " + mSchemaTableName + "";
if(sqlWhereClause.length() > 0)
{
sql += " where " + sqlWhereClause;
}
#endif
PGresult *result = PQexec(connection, (const char *) (sql.utf8()));
QgsDebugMsg("QgsPostgresProvider: Approximate Number of features as text: " + QString(PQgetvalue(result, 0, 0)));
numberFeatures = QString(PQgetvalue(result, 0, 0)).toLong();
PQclear(result);
QgsDebugMsg("QgsPostgresProvider: Approximate Number of features: " + QString::number(numberFeatures));
return numberFeatures;
}
// TODO: use the estimateExtents procedure of PostGIS and PostgreSQL 8
// This tip thanks to #qgis irc nick "creeping"
void QgsPostgresProvider::calculateExtents()
{
#ifdef POSTGRESQL_THREADS
// get the approximate extent by retreiving the bounding box
// of the first few items with a geometry
QString sql = "select box3d(" + geometryColumn + ") from "
+ mSchemaTableName + " where ";
if(sqlWhereClause.length() > 0)
{
sql += "(" + sqlWhereClause + ") and ";
}
sql += "not IsEmpty(" + geometryColumn + ") limit 5";
#if WASTE_TIME
sql = "select xmax(extent(\"" + geometryColumn + "\")) as xmax,"
"xmin(extent(\"" + geometryColumn + "\")) as xmin,"
"ymax(extent(\"" + geometryColumn + "\")) as ymax,"
"ymin(extent(\"" + geometryColumn + "\")) as ymin"
" from " + mSchemaTableName;
#endif
QgsDebugMsg((const char*)(QString("QgsPostgresProvider::calculateExtents - Getting approximate extent using: '") + sql + "'").toLocal8Bit().data());
PGresult *result = PQexec(connection, (const char *) (sql.utf8()));
// TODO: Guard against the result having no rows
for (int i = 0; i < PQntuples(result); i++)
{
std::string box3d = PQgetvalue(result, i, 0);
if (0 == i)
{
// create the initial extent
layerExtent = QgsPostGisBox3d(box3d);
}
else
{
// extend the initial extent
QgsPostGisBox3d b = QgsPostGisBox3d(box3d);
layerExtent.combineExtentWith( &b );
}
QgsDebugMsg("QgsPostgresProvider: After row " + QString::number(i) + ", extent is: " +
QString::number(layerExtent.xMin()) + ", " + QString::number(layerExtent.yMin()) +
" " + QString::number(layerExtent.xMax()) + ", " + QString::number(layerExtent.yMax()));
}
#ifdef QGISDEBUG
QString xMsg;
QTextOStream(&xMsg).precision(18);
QTextOStream(&xMsg).width(18);
QTextOStream(&xMsg) << "QgsPostgresProvider: Set extents to: " << layerExtent.
xMin() << ", " << layerExtent.yMin() << " " << layerExtent.xMax() << ", " << layerExtent.yMax();
QgsDebugMsg(xMsg);
#endif
QgsDebugMsg("QgsPostgresProvider: Set limit 5 extents to: " + QString::number(layerExtent.xMin()) + \
", " + QString::number(layerExtent.yMin()) + " " + QString::number(layerExtent.xMax()) + \
", " + QString::number(layerExtent.yMax()));
// clear query result
PQclear(result);
#else // non-postgresql threads version
// get the extents
QString sql = "select extent(\"" + geometryColumn + "\") from " +
mSchemaTableName;
if(sqlWhereClause.length() > 0)
{
sql += " where " + sqlWhereClause;
}
#if WASTE_TIME
sql = "select xmax(extent(\"" + geometryColumn + "\")) as xmax,"
"xmin(extent(\"" + geometryColumn + "\")) as xmin,"
"ymax(extent(\"" + geometryColumn + "\")) as ymax,"
"ymin(extent(\"" + geometryColumn + "\")) as ymin"
" from " + mSchemaTableName;
#endif
QgsDebugMsg((const char*)(QString("+++++++++QgsPostgresProvider::calculateExtents - Getting extents using schema.table: ") + sql).toLocal8Bit().data());
PGresult *result = PQexec(connection, (const char *) (sql.utf8()));
Q_ASSERT(PQntuples(result) == 1);
std::string box3d = PQgetvalue(result, 0, 0);
if (box3d != "")
{
std::string s;
box3d = box3d.substr(box3d.find_first_of("(")+1);
box3d = box3d.substr(box3d.find_first_not_of(" "));
s = box3d.substr(0, box3d.find_first_of(" "));
double minx = strtod(s.c_str(), NULL);
box3d = box3d.substr(box3d.find_first_of(" ")+1);
s = box3d.substr(0, box3d.find_first_of(" "));
double miny = strtod(s.c_str(), NULL);
box3d = box3d.substr(box3d.find_first_of(",")+1);
box3d = box3d.substr(box3d.find_first_not_of(" "));
s = box3d.substr(0, box3d.find_first_of(" "));
double maxx = strtod(s.c_str(), NULL);
box3d = box3d.substr(box3d.find_first_of(" ")+1);
s = box3d.substr(0, box3d.find_first_of(" "));
double maxy = strtod(s.c_str(), NULL);
layerExtent.setXmax(maxx);
layerExtent.setXmin(minx);
layerExtent.setYmax(maxy);
layerExtent.setYmin(miny);
#ifdef QGISDEBUG
QString xMsg;
QTextOStream(&xMsg).precision(18);
QTextOStream(&xMsg).width(18);
QTextOStream(&xMsg) << "Set extents to: " << layerExtent.
xMin() << ", " << layerExtent.yMin() << " " << layerExtent.xMax() << ", " << layerExtent.yMax();
QgsDebugMsg(xMsg);
#endif
// clear query result
PQclear(result);
}
#endif
}
/**
* Event sink for events from threads
*/
void QgsPostgresProvider::customEvent( QCustomEvent * e )
{
QgsDebugMsg("QgsPostgresProvider: received a custom event " + e->type());
switch ( e->type() )
{
case (QEvent::Type) QGis::ProviderExtentCalcEvent:
QgsDebugMsg("QgsPostgresProvider: extent has been calculated");
// Collect the new extent from the event and set this layer's
// extent with it.
setExtent( (QgsRect*) e->data() );
QgsDebugMsg("QgsPostgresProvider: new extent has been saved");
QgsDebugMsg("QgsPostgresProvider: Set extent to: " + QString::number(layerExtent.xMin()) + ", " +
QString::number(layerExtent.yMin()) + " " + QString::number(layerExtent.xMax()) + ", " +
QString::number(layerExtent.yMax()));
QgsDebugMsg("QgsPostgresProvider: emitting fullExtentCalculated()");
#ifndef WIN32 //temporary hack for native win build
emit fullExtentCalculated();
#endif
// TODO: Only uncomment this when the overview map canvas has been subclassed
// from the QgsMapCanvas
// QgsDebugMsg("QgsPostgresProvider: emitting repaintRequested()");
// emit repaintRequested();
break;
case (QEvent::Type) QGis::ProviderCountCalcEvent:
QgsDebugMsg("QgsPostgresProvider: count has been calculated");
QgsProviderCountCalcEvent* e1 = (QgsProviderCountCalcEvent*) e;
numberFeatures = e1->numberFeatures();
QgsDebugMsg("QgsPostgresProvider: count is " + QString::number(numberFeatures));
break;
}
QgsDebugMsg("QgsPostgresProvider: Finished processing custom event " + QString::number(e->type()));
}
bool QgsPostgresProvider::deduceEndian()
{
// need to store the PostgreSQL endian format used in binary cursors
// since it appears that starting with
// version 7.4, binary cursors return data in XDR whereas previous versions
// return data in the endian of the server
QString firstOid = "select oid from pg_class where relname = '" +
mTableName + "' and relnamespace = (select oid from pg_namespace where nspname = '"
+ mSchemaName + "')";
PGresult * oidResult = PQexec(connection, (const char*)(firstOid.utf8()));
// get the int value from a "normal" select
QString oidValue = PQgetvalue(oidResult,0,0);
PQclear(oidResult);
QgsDebugMsg("Creating binary cursor");
// get the same value using a binary cursor
PQexec(connection,"begin work");
QString oidDeclare = QString("declare oidcursor binary cursor for select oid from pg_class where relname = '%1' and relnamespace = (select oid from pg_namespace where nspname = '%2')").arg(mTableName).arg(mSchemaName);
// set up the cursor
PQexec(connection, (const char *)oidDeclare);
QString fetch = "fetch forward 1 from oidcursor";
QgsDebugMsg("Fetching a record and attempting to get check endian-ness");
PGresult *fResult = PQexec(connection, (const char *)fetch);
PQexec(connection, "end work");
swapEndian = true;
if(PQntuples(fResult) > 0){
// get the oid value from the binary cursor
int oid = *(int *)PQgetvalue(fResult,0,0);
//QgsDebugMsg("Got oid of " << oid << " from the binary cursor");
//QgsDebugMsg("First oid is " QString::number(oidValue));
// compare the two oid values to determine if we need to do an endian swap
if(oid == oidValue.toInt())
swapEndian = false;
PQclear(fResult);
}
return swapEndian;
}
bool QgsPostgresProvider::getGeometryDetails()
{
QString fType("");
srid = "";
valid = false;
QStringList log;
QString sql = "select f_geometry_column,type,srid from geometry_columns"
" where f_table_name='" + mTableName + "' and f_geometry_column = '" +
geometryColumn + "' and f_table_schema = '" + mSchemaName + "'";
QgsDebugMsg("Getting geometry column: " + sql);
PGresult *result = executeDbCommand(connection, sql);
QgsDebugMsg("geometry column query returned " + PQntuples(result));
QgsDebugMsg("column number of srid is " + QString::number(PQfnumber(result, "srid")));
if (PQntuples(result) > 0)
{
srid = PQgetvalue(result, 0, PQfnumber(result, "srid"));
fType = PQgetvalue(result, 0, PQfnumber(result, "type"));
PQclear(result);
}
else
{
// Didn't find what we need in the geometry_columns table, so
// get stuff from the relevant column instead. This may (will?)
// fail if there is no data in the relevant table.
PQclear(result); // for the query just before the if() statement
sql = "select "
"srid(\"" + geometryColumn + "\"), "
"geometrytype(\"" + geometryColumn + "\") from " +
mSchemaTableName + " limit 1";
result = executeDbCommand(connection, sql);
if (PQntuples(result) > 0)
{
srid = PQgetvalue(result, 0, PQfnumber(result, "srid"));
fType = PQgetvalue(result, 0, PQfnumber(result, "geometrytype"));
}
PQclear(result);
}
if (!srid.isEmpty() && !fType.isEmpty())
{
valid = true;
if (fType == "POINT")
{
geomType = QGis::WKBPoint;
}
else if(fType == "MULTIPOINT")
{
geomType = QGis::WKBMultiPoint;
}
else if(fType == "LINESTRING")
{
geomType = QGis::WKBLineString;
}
else if(fType == "MULTILINESTRING")
{
geomType = QGis::WKBMultiLineString;
}
else if (fType == "POLYGON")
{
geomType = QGis::WKBPolygon;
}
else if(fType == "MULTIPOLYGON")
{
geomType = QGis::WKBMultiPolygon;
}
else
{
showMessageBox(tr("Unknown geometry type"),
tr("Column ") + geometryColumn + tr(" in ") +
mSchemaTableName + tr(" has a geometry type of ") +
fType + tr(", which Qgis does not currently support."));
valid = false;
}
}
else // something went wrong...
{
log.prepend(tr("Qgis was unable to determine the type and srid of "
"column " + geometryColumn + tr(" in ") +
mSchemaTableName +
tr(". The database communication log was:\n")));
showMessageBox(tr("Unable to get feature type and srid"), log);
}
if (valid)
{
QgsDebugMsg("SRID is " + srid);
QgsDebugMsg("type is " + fType);
QgsDebugMsg("Feature type is " + geomType);
QgsDebugMsg(QString("Feature type name is ") + QGis::qgisFeatureTypes[geomType]);
}
else
{
QgsDebugMsg("Failed to get geometry details for Postgres layer.");
}
return valid;
}
PGresult* QgsPostgresProvider::executeDbCommand(PGconn* connection,
const QString& sql)
{
PGresult *result = PQexec(connection, (const char *) (sql.utf8()));
QgsDebugMsg("Executed SQL: " + sql);
if (PQresultStatus(result) == PGRES_TUPLES_OK)
{
QgsDebugMsg("Command was successful.");
}
else
{
QgsDebugMsg("Command was unsuccessful. The error message was: " + QString(PQresultErrorMessage(result)));
}
return result;
}
void QgsPostgresProvider::showMessageBox(const QString& title,
const QString& text)
{
QgsMessageViewer* message = new QgsMessageViewer();
message->setCaption(title);
message->setMessageAsPlainText(text);
message->exec(); // modal
}
void QgsPostgresProvider::showMessageBox(const QString& title,
const QStringList& text)
{
showMessageBox(title, text.join("\n"));
}
int QgsPostgresProvider::getSrid()
{
return srid.toInt();
}
size_t QgsPostgresProvider::layerCount() const
{
return 1; // XXX need to return actual number of layers
} // QgsPostgresProvider::layerCount()
QString QgsPostgresProvider::name() const
{
return POSTGRES_KEY;
} // QgsPostgresProvider::name()
QString QgsPostgresProvider::description() const
{
return POSTGRES_DESCRIPTION;
} // QgsPostgresProvider::description()
/**
* Class factory to return a pointer to a newly created
* QgsPostgresProvider object
*/
QGISEXTERN QgsPostgresProvider * classFactory(const QString *uri)
{
return new QgsPostgresProvider(*uri);
}
/** Required key function (used to map the plugin to a data store type)
*/
QGISEXTERN QString providerKey()
{
return POSTGRES_KEY;
}
/**
* Required description function
*/
QGISEXTERN QString description()
{
return POSTGRES_DESCRIPTION;
}
/**
* Required isProvider function. Used to determine if this shared library
* is a data provider plugin
*/
QGISEXTERN bool isProvider(){
return true;
}
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