# -*- coding: utf-8 -*-
"""
***************************************************************************
postgis.py
---------------------
Date : November 2012
Copyright : (C) 2012 by Martin Dobias
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. *
* *
***************************************************************************
"""
from __future__ import print_function
from builtins import map
from builtins import str
from builtins import range
from builtins import object
__author__ = 'Martin Dobias'
__date__ = 'November 2012'
__copyright__ = '(C) 2012, Martin Dobias'
# This will get replaced with a git SHA1 when you do a git archive
__revision__ = '$Format:%H$'
import psycopg2
import psycopg2.extensions # For isolation levels
import re
from qgis.PyQt.QtCore import QSettings
from qgis.core import QgsDataSourceUri, QgsCredentials
# Use unicode!
psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
def uri_from_name(conn_name):
settings = QSettings()
settings.beginGroup(u"/PostgreSQL/connections/%s" % conn_name)
if not settings.contains("database"): # non-existent entry?
raise DbError('There is no defined database connection "%s".' % conn_name)
uri = QgsDataSourceUri()
settingsList = ["service", "host", "port", "database", "username", "password", "authcfg"]
service, host, port, database, username, password, authcfg = [settings.value(x, "", type=str) for x in settingsList]
useEstimatedMetadata = settings.value("estimatedMetadata", False, type=bool)
sslmode = settings.value("sslmode", QgsDataSourceUri.SslPrefer, type=int)
settings.endGroup()
if hasattr(authcfg, 'isNull') and authcfg.isNull():
authcfg = ''
if service:
uri.setConnection(service, database, username, password, sslmode, authcfg)
else:
uri.setConnection(host, port, database, username, password, sslmode, authcfg)
uri.setUseEstimatedMetadata(useEstimatedMetadata)
return uri
class TableAttribute(object):
def __init__(self, row):
(self.num,
self.name,
self.data_type,
self.char_max_len,
self.modifier,
self.notnull,
self.hasdefault,
self.default,
) = row
class TableConstraint(object):
"""Class that represents a constraint of a table (relation).
"""
(TypeCheck, TypeForeignKey, TypePrimaryKey, TypeUnique) = list(range(4))
types = {
'c': TypeCheck,
'f': TypeForeignKey,
'p': TypePrimaryKey,
'u': TypeUnique,
}
on_action = {
'a': 'NO ACTION',
'r': 'RESTRICT',
'c': 'CASCADE',
'n': 'SET NULL',
'd': 'SET DEFAULT',
}
match_types = {'u': 'UNSPECIFIED', 'f': 'FULL', 'p': 'PARTIAL'}
def __init__(self, row):
(self.name, con_type, self.is_defferable, self.is_deffered, keys) = row[:5]
self.keys = list(map(int, keys.split(' ')))
self.con_type = TableConstraint.types[con_type] # Convert to enum
if self.con_type == TableConstraint.TypeCheck:
self.check_src = row[5]
elif self.con_type == TableConstraint.TypeForeignKey:
self.foreign_table = row[6]
self.foreign_on_update = TableConstraint.on_action[row[7]]
self.foreign_on_delete = TableConstraint.on_action[row[8]]
self.foreign_match_type = TableConstraint.match_types[row[9]]
self.foreign_keys = row[10]
class TableIndex(object):
def __init__(self, row):
(self.name, columns) = row
self.columns = list(map(int, columns.split(' ')))
class DbError(Exception):
def __init__(self, message, query=None):
self.message = message
self.query = query
def __str__(self):
return str(self).encode('utf-8')
def __unicode__(self):
text = u'MESSAGE: %s' % self.message
if self.query:
text += u'\nQUERY: %s' % self.query
return text
class TableField(object):
def __init__(self, name, data_type, is_null=None, default=None,
modifier=None):
(self.name, self.data_type, self.is_null, self.default,
self.modifier) = (name, data_type, is_null, default, modifier)
def is_null_txt(self):
if self.is_null:
return 'NULL'
else:
return 'NOT NULL'
def field_def(self):
"""Return field definition as used for CREATE TABLE or
ALTER TABLE command.
"""
data_type = (self.data_type if not self.modifier or self.modifier
< 0 else '%s(%d)' % (self.data_type, self.modifier))
txt = '%s %s %s' % (self._quote(self.name), data_type,
self.is_null_txt())
if self.default and len(self.default) > 0:
txt += ' DEFAULT %s' % self.default
return txt
def _quote(self, ident):
if re.match(r"^\w+$", ident) is not None:
return ident
else:
return '"%s"' % ident.replace('"', '""')
class GeoDB(object):
@classmethod
def from_name(cls, conn_name):
uri = uri_from_name(conn_name)
return cls(uri=uri)
def __init__(self, host=None, port=None, dbname=None, user=None,
passwd=None, service=None, uri=None):
# Regular expression for identifiers without need to quote them
self.re_ident_ok = re.compile(r"^\w+$")
port = str(port)
if uri:
self.uri = uri
else:
self.uri = QgsDataSourceUri()
if service:
self.uri.setConnection(service, dbname, user, passwd)
else:
self.uri.setConnection(host, port, dbname, user, passwd)
conninfo = self.uri.connectionInfo(False)
err = None
for i in range(4):
expandedConnInfo = self.uri.connectionInfo(True)
try:
self.con = psycopg2.connect(expandedConnInfo)
if err is not None:
QgsCredentials.instance().put(conninfo,
self.uri.username(),
self.uri.password())
break
except psycopg2.OperationalError as e:
if i == 3:
raise DbError(str(e))
err = str(e)
user = self.uri.username()
password = self.uri.password()
(ok, user, password) = QgsCredentials.instance().get(conninfo,
user,
password,
err)
if not ok:
raise DbError(u'Action cancelled by user')
if user:
self.uri.setUsername(user)
if password:
self.uri.setPassword(password)
finally:
# remove certs (if any) of the expanded connectionInfo
expandedUri = QgsDataSourceUri(expandedConnInfo)
sslCertFile = expandedUri.param("sslcert")
if sslCertFile:
sslCertFile = sslCertFile.replace("'", "")
os.remove(sslCertFile)
sslKeyFile = expandedUri.param("sslkey")
if sslKeyFile:
sslKeyFile = sslKeyFile.replace("'", "")
os.remove(sslKeyFile)
sslCAFile = expandedUri.param("sslrootcert")
if sslCAFile:
sslCAFile = sslCAFile.replace("'", "")
os.remove(sslCAFile)
self.has_postgis = self.check_postgis()
def get_info(self):
c = self.con.cursor()
self._exec_sql(c, 'SELECT version()')
return c.fetchone()[0]
def check_postgis(self):
"""Check whether postgis_version is present in catalog.
"""
c = self.con.cursor()
self._exec_sql(c,
"SELECT COUNT(*) FROM pg_proc WHERE proname = 'postgis_version'")
return c.fetchone()[0] > 0
def get_postgis_info(self):
"""Returns tuple about postgis support:
- lib version
- installed scripts version
- released scripts version
- geos version
- proj version
- whether uses stats
"""
c = self.con.cursor()
self._exec_sql(c,
'SELECT postgis_lib_version(), postgis_scripts_installed(), \
postgis_scripts_released(), postgis_geos_version(), \
postgis_proj_version(), postgis_uses_stats()')
return c.fetchone()
def list_schemas(self):
"""Get list of schemas in tuples: (oid, name, owner, perms).
"""
c = self.con.cursor()
sql = "SELECT oid, nspname, pg_get_userbyid(nspowner), nspacl \
FROM pg_namespace \
WHERE nspname !~ '^pg_' AND nspname != 'information_schema'"
self._exec_sql(c, sql)
return c.fetchall()
def list_geotables(self, schema=None):
"""Get list of tables with schemas, whether user has privileges,
whether table has geometry column(s) etc.
Geometry_columns:
- f_table_schema
- f_table_name
- f_geometry_column
- coord_dimension
- srid
- type
"""
c = self.con.cursor()
if schema:
schema_where = " AND nspname = '%s' " % self._quote_unicode(schema)
else:
schema_where = \
" AND (nspname != 'information_schema' AND nspname !~ 'pg_') "
# LEFT OUTER JOIN: like LEFT JOIN but if there are more matches,
# for join, all are used (not only one)
# First find out whether postgis is enabled
if not self.has_postgis:
# Get all tables and views
sql = """SELECT pg_class.relname, pg_namespace.nspname,
pg_class.relkind, pg_get_userbyid(relowner),
reltuples, relpages, NULL, NULL, NULL, NULL
FROM pg_class
JOIN pg_namespace ON pg_namespace.oid = pg_class.relnamespace
WHERE pg_class.relkind IN ('v', 'r')""" \
+ schema_where + 'ORDER BY nspname, relname'
else:
# Discovery of all tables and whether they contain a
# geometry column
sql = """SELECT pg_class.relname, pg_namespace.nspname,
pg_class.relkind, pg_get_userbyid(relowner),
reltuples, relpages, pg_attribute.attname,
pg_attribute.atttypid::regtype, NULL, NULL
FROM pg_class
JOIN pg_namespace ON pg_namespace.oid = pg_class.relnamespace
LEFT OUTER JOIN pg_attribute ON
pg_attribute.attrelid = pg_class.oid AND
(pg_attribute.atttypid = 'geometry'::regtype
OR pg_attribute.atttypid IN
(SELECT oid FROM pg_type
WHERE typbasetype='geometry'::regtype))
WHERE pg_class.relkind IN ('v', 'r') """ \
+ schema_where + 'ORDER BY nspname, relname, attname'
self._exec_sql(c, sql)
items = c.fetchall()
# Get geometry info from geometry_columns if exists
if self.has_postgis:
sql = """SELECT relname, nspname, relkind,
pg_get_userbyid(relowner), reltuples, relpages,
geometry_columns.f_geometry_column,
geometry_columns.type,
geometry_columns.coord_dimension,
geometry_columns.srid
FROM pg_class
JOIN pg_namespace ON relnamespace=pg_namespace.oid
LEFT OUTER JOIN geometry_columns ON
relname=f_table_name AND nspname=f_table_schema
WHERE (relkind = 'r' or relkind='v') """ \
+ schema_where + 'ORDER BY nspname, relname, \
f_geometry_column'
self._exec_sql(c, sql)
# Merge geometry info to "items"
for (i, geo_item) in enumerate(c.fetchall()):
if geo_item[7]:
items[i] = geo_item
return items
def get_table_rows(self, table, schema=None):
c = self.con.cursor()
self._exec_sql(c, 'SELECT COUNT(*) FROM %s' % self._table_name(schema,
table))
return c.fetchone()[0]
def get_table_fields(self, table, schema=None):
"""Return list of columns in table"""
c = self.con.cursor()
schema_where = (" AND nspname='%s' "
% self._quote_unicode(schema) if schema is not None else ''
)
sql = """SELECT a.attnum AS ordinal_position,
a.attname AS column_name,
t.typname AS data_type,
a.attlen AS char_max_len,
a.atttypmod AS modifier,
a.attnotnull AS notnull,
a.atthasdef AS hasdefault,
adef.adsrc AS default_value
FROM pg_class c
JOIN pg_attribute a ON a.attrelid = c.oid
JOIN pg_type t ON a.atttypid = t.oid
JOIN pg_namespace nsp ON c.relnamespace = nsp.oid
LEFT JOIN pg_attrdef adef ON adef.adrelid = a.attrelid
AND adef.adnum = a.attnum
WHERE
c.relname = '%s' %s AND
a.attnum > 0
ORDER BY a.attnum""" \
% (self._quote_unicode(table), schema_where)
self._exec_sql(c, sql)
attrs = []
for row in c.fetchall():
attrs.append(TableAttribute(row))
return attrs
def get_table_indexes(self, table, schema=None):
"""Get info about table's indexes. ignore primary key and unique
index, they get listed in constraints.
"""
c = self.con.cursor()
schema_where = (" AND nspname='%s' "
% self._quote_unicode(schema) if schema is not None else ''
)
sql = """SELECT relname, indkey
FROM pg_class, pg_index
WHERE pg_class.oid = pg_index.indexrelid AND pg_class.oid IN (
SELECT indexrelid
FROM pg_index, pg_class
JOIN pg_namespace nsp ON pg_class.relnamespace = nsp.oid
WHERE pg_class.relname='%s' %s AND
pg_class.oid=pg_index.indrelid
AND indisunique != 't' AND indisprimary != 't' )""" \
% (self._quote_unicode(table), schema_where)
self._exec_sql(c, sql)
indexes = []
for row in c.fetchall():
indexes.append(TableIndex(row))
return indexes
def get_table_constraints(self, table, schema=None):
c = self.con.cursor()
schema_where = (" AND nspname='%s' "
% self._quote_unicode(schema) if schema is not None else ''
)
sql = """SELECT c.conname, c.contype, c.condeferrable, c.condeferred,
array_to_string(c.conkey, ' '), c.consrc, t2.relname,
c.confupdtype, c.confdeltype, c.confmatchtype,
array_to_string(c.confkey, ' ')
FROM pg_constraint c
LEFT JOIN pg_class t ON c.conrelid = t.oid
LEFT JOIN pg_class t2 ON c.confrelid = t2.oid
JOIN pg_namespace nsp ON t.relnamespace = nsp.oid
WHERE t.relname = '%s' %s """ \
% (self._quote_unicode(table), schema_where)
self._exec_sql(c, sql)
constrs = []
for row in c.fetchall():
constrs.append(TableConstraint(row))
return constrs
def get_view_definition(self, view, schema=None):
"""Returns definition of the view."""
schema_where = (" AND nspname='%s' "
% self._quote_unicode(schema) if schema is not None else ''
)
sql = """SELECT pg_get_viewdef(c.oid)
FROM pg_class c
JOIN pg_namespace nsp ON c.relnamespace = nsp.oid
WHERE relname='%s' %s AND relkind='v'""" \
% (self._quote_unicode(view), schema_where)
c = self.con.cursor()
self._exec_sql(c, sql)
return c.fetchone()[0]
def add_geometry_column(self, table, geom_type, schema=None,
geom_column='the_geom', srid=-1, dim=2):
# Use schema if explicitly specified
if schema:
schema_part = "'%s', " % self._quote_unicode(schema)
else:
schema_part = ''
sql = "SELECT AddGeometryColumn(%s'%s', '%s', %d, '%s', %d)" % (
schema_part,
self._quote_unicode(table),
self._quote_unicode(geom_column),
srid,
self._quote_unicode(geom_type),
dim,
)
self._exec_sql_and_commit(sql)
def delete_geometry_column(self, table, geom_column, schema=None):
"""Use PostGIS function to delete geometry column correctly."""
if schema:
schema_part = "'%s', " % self._quote_unicode(schema)
else:
schema_part = ''
sql = "SELECT DropGeometryColumn(%s'%s', '%s')" % (schema_part,
self._quote_unicode(table), self._quote_unicode(geom_column))
self._exec_sql_and_commit(sql)
def delete_geometry_table(self, table, schema=None):
"""Delete table with one or more geometries using postgis function."""
if schema:
schema_part = "'%s', " % self._quote_unicode(schema)
else:
schema_part = ''
sql = "SELECT DropGeometryTable(%s'%s')" % (schema_part,
self._quote_unicode(table))
self._exec_sql_and_commit(sql)
def create_table(self, table, fields, pkey=None, schema=None):
"""Create ordinary table.
'fields' is array containing instances of TableField
'pkey' contains name of column to be used as primary key
"""
if len(fields) == 0:
return False
table_name = self._table_name(schema, table)
sql = 'CREATE TABLE %s (%s' % (table_name, fields[0].field_def())
for field in fields[1:]:
sql += ', %s' % field.field_def()
if pkey:
sql += ', PRIMARY KEY (%s)' % self._quote(pkey)
sql += ')'
self._exec_sql_and_commit(sql)
return True
def delete_table(self, table, schema=None):
"""Delete table from the database."""
table_name = self._table_name(schema, table)
sql = 'DROP TABLE %s' % table_name
self._exec_sql_and_commit(sql)
def empty_table(self, table, schema=None):
"""Delete all rows from table."""
table_name = self._table_name(schema, table)
sql = 'DELETE FROM %s' % table_name
self._exec_sql_and_commit(sql)
def rename_table(self, table, new_table, schema=None):
"""Rename a table in database."""
table_name = self._table_name(schema, table)
sql = 'ALTER TABLE %s RENAME TO %s' % (table_name,
self._quote(new_table))
self._exec_sql_and_commit(sql)
# Update geometry_columns if postgis is enabled
if self.has_postgis:
sql = "UPDATE geometry_columns SET f_table_name='%s' \
WHERE f_table_name='%s'" \
% (self._quote_unicode(new_table), self._quote_unicode(table))
if schema is not None:
sql += " AND f_table_schema='%s'" % self._quote_unicode(schema)
self._exec_sql_and_commit(sql)
def create_view(self, name, query, schema=None):
view_name = self._table_name(schema, name)
sql = 'CREATE VIEW %s AS %s' % (view_name, query)
self._exec_sql_and_commit(sql)
def delete_view(self, name, schema=None):
view_name = self._table_name(schema, name)
sql = 'DROP VIEW %s' % view_name
self._exec_sql_and_commit(sql)
def rename_view(self, name, new_name, schema=None):
"""Rename view in database."""
self.rename_table(name, new_name, schema)
def create_schema(self, schema):
"""Create a new empty schema in database."""
sql = 'CREATE SCHEMA %s' % self._quote(schema)
self._exec_sql_and_commit(sql)
def delete_schema(self, schema):
"""Drop (empty) schema from database."""
sql = 'DROP SCHEMA %s' % self._quote(schema)
self._exec_sql_and_commit(sql)
def rename_schema(self, schema, new_schema):
"""Rename a schema in database."""
sql = 'ALTER SCHEMA %s RENAME TO %s' % (self._quote(schema),
self._quote(new_schema))
self._exec_sql_and_commit(sql)
# Update geometry_columns if postgis is enabled
if self.has_postgis:
sql = \
"UPDATE geometry_columns SET f_table_schema='%s' \
WHERE f_table_schema='%s'" \
% (self._quote_unicode(new_schema), self._quote_unicode(schema))
self._exec_sql_and_commit(sql)
def table_add_column(self, table, field, schema=None):
"""Add a column to table (passed as TableField instance)."""
table_name = self._table_name(schema, table)
sql = 'ALTER TABLE %s ADD %s' % (table_name, field.field_def())
self._exec_sql_and_commit(sql)
def table_delete_column(self, table, field, schema=None):
"""Delete column from a table."""
table_name = self._table_name(schema, table)
sql = 'ALTER TABLE %s DROP %s' % (table_name, self._quote(field))
self._exec_sql_and_commit(sql)
def table_column_rename(self, table, name, new_name, schema=None):
"""Rename column in a table."""
table_name = self._table_name(schema, table)
sql = 'ALTER TABLE %s RENAME %s TO %s' % (table_name,
self._quote(name), self._quote(new_name))
self._exec_sql_and_commit(sql)
# Update geometry_columns if postgis is enabled
if self.has_postgis:
sql = "UPDATE geometry_columns SET f_geometry_column='%s' \
WHERE f_geometry_column='%s' AND f_table_name='%s'" \
% (self._quote_unicode(new_name), self._quote_unicode(name),
self._quote_unicode(table))
if schema is not None:
sql += " AND f_table_schema='%s'" % self._quote(schema)
self._exec_sql_and_commit(sql)
def table_column_set_type(self, table, column, data_type, schema=None):
"""Change column type."""
table_name = self._table_name(schema, table)
sql = 'ALTER TABLE %s ALTER %s TYPE %s' % (table_name,
self._quote(column), data_type)
self._exec_sql_and_commit(sql)
def table_column_set_default(self, table, column, default, schema=None):
"""Change column's default value.
If default=None drop default value.
"""
table_name = self._table_name(schema, table)
if default:
sql = 'ALTER TABLE %s ALTER %s SET DEFAULT %s' % (table_name,
self._quote(column), default)
else:
sql = 'ALTER TABLE %s ALTER %s DROP DEFAULT' % (table_name,
self._quote(column))
self._exec_sql_and_commit(sql)
def table_column_set_null(self, table, column, is_null, schema=None):
"""Change whether column can contain null values."""
table_name = self._table_name(schema, table)
sql = 'ALTER TABLE %s ALTER %s ' % (table_name, self._quote(column))
if is_null:
sql += 'DROP NOT NULL'
else:
sql += 'SET NOT NULL'
self._exec_sql_and_commit(sql)
def table_add_primary_key(self, table, column, schema=None):
"""Add a primery key (with one column) to a table."""
table_name = self._table_name(schema, table)
sql = 'ALTER TABLE %s ADD PRIMARY KEY (%s)' % (table_name,
self._quote(column))
self._exec_sql_and_commit(sql)
def table_add_unique_constraint(self, table, column, schema=None):
"""Add a unique constraint to a table."""
table_name = self._table_name(schema, table)
sql = 'ALTER TABLE %s ADD UNIQUE (%s)' % (table_name,
self._quote(column))
self._exec_sql_and_commit(sql)
def table_delete_constraint(self, table, constraint, schema=None):
"""Delete constraint in a table."""
table_name = self._table_name(schema, table)
sql = 'ALTER TABLE %s DROP CONSTRAINT %s' % (table_name,
self._quote(constraint))
self._exec_sql_and_commit(sql)
def table_move_to_schema(self, table, new_schema, schema=None):
if new_schema == schema:
return
table_name = self._table_name(schema, table)
sql = 'ALTER TABLE %s SET SCHEMA %s' % (table_name,
self._quote(new_schema))
self._exec_sql_and_commit(sql)
# Update geometry_columns if postgis is enabled
if self.has_postgis:
sql = "UPDATE geometry_columns SET f_table_schema='%s' \
WHERE f_table_name='%s'" \
% (self._quote_unicode(new_schema), self._quote_unicode(table))
if schema is not None:
sql += " AND f_table_schema='%s'" % self._quote_unicode(schema)
self._exec_sql_and_commit(sql)
def create_index(self, table, name, column, schema=None):
"""Create index on one column using default options."""
table_name = self._table_name(schema, table)
idx_name = self._quote(name)
sql = 'CREATE INDEX %s ON %s (%s)' % (idx_name, table_name,
self._quote(column))
self._exec_sql_and_commit(sql)
def create_spatial_index(self, table, schema=None, geom_column='the_geom'):
table_name = self._table_name(schema, table)
idx_name = self._quote(u"sidx_%s_%s" % (table, geom_column))
sql = 'CREATE INDEX %s ON %s USING GIST(%s)' % (idx_name, table_name,
self._quote(geom_column))
self._exec_sql_and_commit(sql)
def delete_index(self, name, schema=None):
index_name = self._table_name(schema, name)
sql = 'DROP INDEX %s' % index_name
self._exec_sql_and_commit(sql)
def get_database_privileges(self):
"""DB privileges: (can create schemas, can create temp. tables).
"""
sql = "SELECT has_database_privilege('%(d)s', 'CREATE'), \
has_database_privilege('%(d)s', 'TEMP')" \
% {'d': self._quote_unicode(self.dbname)}
c = self.con.cursor()
self._exec_sql(c, sql)
return c.fetchone()
def get_schema_privileges(self, schema):
"""Schema privileges: (can create new objects, can access objects
in schema)."""
sql = "SELECT has_schema_privilege('%(s)s', 'CREATE'), \
has_schema_privilege('%(s)s', 'USAGE')" \
% {'s': self._quote_unicode(schema)}
c = self.con.cursor()
self._exec_sql(c, sql)
return c.fetchone()
def get_table_privileges(self, table, schema=None):
"""Table privileges: (select, insert, update, delete).
"""
t = self._table_name(schema, table)
sql = """SELECT has_table_privilege('%(t)s', 'SELECT'),
has_table_privilege('%(t)s', 'INSERT'),
has_table_privilege('%(t)s', 'UPDATE'),
has_table_privilege('%(t)s', 'DELETE')""" \
% {'t': self._quote_unicode(t)}
c = self.con.cursor()
self._exec_sql(c, sql)
return c.fetchone()
def vacuum_analyze(self, table, schema=None):
"""Run VACUUM ANALYZE on a table."""
t = self._table_name(schema, table)
# VACUUM ANALYZE must be run outside transaction block - we
# have to change isolation level
self.con.set_isolation_level(
psycopg2.extensions.ISOLATION_LEVEL_AUTOCOMMIT)
c = self.con.cursor()
self._exec_sql(c, 'VACUUM ANALYZE %s' % t)
self.con.set_isolation_level(
psycopg2.extensions.ISOLATION_LEVEL_READ_COMMITTED)
def sr_info_for_srid(self, srid):
if not self.has_postgis:
return 'Unknown'
try:
c = self.con.cursor()
self._exec_sql(c,
"SELECT srtext FROM spatial_ref_sys WHERE srid = '%d'"
% srid)
srtext = c.fetchone()[0]
# Try to extract just SR name (should be qouted in double
# quotes)
x = re.search('"([^"]+)"', srtext)
if x is not None:
srtext = x.group()
return srtext
except DbError:
return 'Unknown'
def insert_table_row(self, table, values, schema=None, cursor=None):
"""Insert a row with specified values to a table.
If a cursor is specified, it doesn't commit (expecting that
there will be more inserts) otherwise it commits immediately.
"""
t = self._table_name(schema, table)
sql = ''
for value in values:
# TODO: quote values?
if sql:
sql += ', '
sql += value
sql = 'INSERT INTO %s VALUES (%s)' % (t, sql)
if cursor:
self._exec_sql(cursor, sql)
else:
self._exec_sql_and_commit(sql)
def _exec_sql(self, cursor, sql):
try:
cursor.execute(sql)
except psycopg2.Error as e:
raise DbError(str(e), e.cursor.query)
def _exec_sql_and_commit(self, sql):
"""Tries to execute and commit some action, on error it rolls
back the change.
"""
try:
c = self.con.cursor()
self._exec_sql(c, sql)
self.con.commit()
except DbError:
self.con.rollback()
raise
def _quote(self, identifier):
"""Quote identifier if needed."""
# Make sure it's python unicode string
identifier = str(identifier)
# Is it needed to quote the identifier?
if self.re_ident_ok.match(identifier) is not None:
return identifier
# It's needed - let's quote it (and double the double-quotes)
return u'"%s"' % identifier.replace('"', '""')
def _quote_unicode(self, txt):
"""Make the string safe - replace ' with ''.
"""
# make sure it's python unicode string
txt = str(txt)
return txt.replace("'", "''")
def _table_name(self, schema, table):
if not schema:
return self._quote(table)
else:
return u'%s.%s' % (self._quote(schema), self._quote(table))
# For debugging / testing
if __name__ == '__main__':
db = GeoDB(host='localhost', dbname='gis', user='gisak', passwd='g')
# fix_print_with_import
print(db.list_schemas())
# fix_print_with_import
print('==========')
for row in db.list_geotables():
# fix_print_with_import
print(row)
# fix_print_with_import
print('==========')
for row in db.get_table_indexes('trencin'):
# fix_print_with_import
print(row)
# fix_print_with_import
print('==========')
for row in db.get_table_constraints('trencin'):
# fix_print_with_import
print(row)
# fix_print_with_import
print('==========')
# fix_print_with_import
print(db.get_table_rows('trencin'))
# for fld in db.get_table_metadata('trencin'):
# ....print fld
# try:
# ....db.create_table('trrrr', [('id','serial'), ('test','text')])
# except DbError, e:
# ....print unicode(e), e.query