2013-08-20 09:22:03 +02:00

129 lines
4.7 KiB
Python

# -*- coding: utf-8 -*-
"""
***************************************************************************
ogrsql.py
---------------------
Date : November 2012
Copyright : (C) 2012 by Victor Olaya
Email : volayaf at gmail dot 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. *
* *
***************************************************************************
"""
__author__ = 'Victor Olaya'
__date__ = 'November 2012'
__copyright__ = '(C) 2012, Victor Olaya'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
from processing.outputs.OutputHTML import OutputHTML
from processing.parameters.ParameterVector import ParameterVector
from processing.parameters.ParameterString import ParameterString
from processing.core.ProcessingLog import ProcessingLog
from qgis.core import *
from PyQt4.QtCore import *
from PyQt4.QtGui import *
import string
import re
try:
from osgeo import ogr
ogrAvailable = True
except:
ogrAvailable = False
from processing.gdal.OgrAlgorithm import OgrAlgorithm
class OgrSql(OgrAlgorithm):
#constants used to refer to parameters and outputs.
#They will be used when calling the algorithm from another algorithm,
#or when calling from the QGIS console.
OUTPUT = "OUTPUT"
INPUT_LAYER = "INPUT_LAYER"
SQL = "SQL"
def defineCharacteristics(self):
self.name = "Execute SQL"
self.group = "[OGR] Miscellaneous"
#we add the input vector layer. It can have any kind of geometry
#It is a mandatory (not optional) one, hence the False argument
self.addParameter(ParameterVector(self.INPUT_LAYER, "Input layer", [ParameterVector.VECTOR_TYPE_ANY], False))
self.addParameter(ParameterString(self.SQL, "SQL", ""))
self.addOutput(OutputHTML(self.OUTPUT, "SQL result"))
def processAlgorithm(self, progress):
if not ogrAvailable:
ProcessingLog.addToLog(ProcessingLog.LOG_ERROR, "OGR bindings not installed" )
return
input = self.getParameterValue(self.INPUT_LAYER)
sql = self.getParameterValue(self.SQL)
ogrLayer = self.ogrConnectionString(input)
output = self.getOutputValue(self.OUTPUT)
qDebug("Opening data source '%s'" % ogrLayer)
poDS = ogr.Open( ogrLayer, False )
if poDS is None:
ProcessingLog.addToLog(ProcessingLog.LOG_ERROR, self.failure(ogrLayer))
return
result = self.select_values(poDS, sql)
f = open(output, "w")
f.write("<table>")
for row in result:
f.write("<tr>")
for col in row:
f.write("<td>"+col+"</td>")
f.write("</tr>")
f.write("</table>")
f.close()
def execute_sql(self, ds, sql_statement):
poResultSet = ds.ExecuteSQL( sql_statement, None, None )
if poResultSet is not None:
ds.ReleaseResultSet( poResultSet )
def select_values(self, ds, sql_statement):
"""Returns an array of the columns and values of select statement:
select_values(ds, "SELECT id FROM companies") => [['id'],[1],[2],[3]]
"""
poResultSet = ds.ExecuteSQL( sql_statement, None, None )
#TODO: redirect error messages
fields = []
rows = []
if poResultSet is not None:
poDefn = poResultSet.GetLayerDefn()
for iField in range(poDefn.GetFieldCount()):
poFDefn = poDefn.GetFieldDefn(iField)
fields.append(poFDefn.GetNameRef())
#poGeometry = poFeature.GetGeometryRef()
#if poGeometry is not None:
# line = (" %s = [GEOMETRY]" % poGeometry.GetGeometryName() )
poFeature = poResultSet.GetNextFeature()
while poFeature is not None:
values = []
for iField in range(poDefn.GetFieldCount()):
if poFeature.IsFieldSet( iField ):
values.append(poFeature.GetFieldAsString( iField ))
else:
values.append("(null)")
rows.append(values)
poFeature = poResultSet.GetNextFeature()
ds.ReleaseResultSet( poResultSet )
return [fields] + rows