Merge pull request #2458 from SebDieBln/Postgres_GeomTypeDirect

[postgresprovider] Determine geometry type and srid directly from column type
qgis · Nov 18, 2015 · 8e5ba3b · 8e5ba3b
2 parents f6e4e75 + cfa308d
commit 8e5ba3b
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Showing 4 changed files with 52 additions and 1 deletion.
diff --git a/src/providers/postgres/qgspostgresconn.cpp b/src/providers/postgres/qgspostgresconn.cpp
@@ -124,6 +124,12 @@ int QgsPostgresResult::PQftype( int col )
   return ::PQftype( mRes, col );
 }
 
+int QgsPostgresResult::PQfmod( int col )
+{
+  Q_ASSERT( mRes );
+  return ::PQfmod( mRes, col );
+}
+
 Oid QgsPostgresResult::PQoidValue()
 {
   Q_ASSERT( mRes );

diff --git a/src/providers/postgres/qgspostgresconn.h b/src/providers/postgres/qgspostgresconn.h
@@ -167,6 +167,7 @@ class QgsPostgresResult
     QString PQfname( int col );
     int PQftable( int col );
     int PQftype( int col );
+    int PQfmod( int col );
     int PQftablecol( int col );
     Oid PQoidValue();
 

diff --git a/src/providers/postgres/qgspostgresprovider.cpp b/src/providers/postgres/qgspostgresprovider.cpp
@@ -2915,7 +2915,43 @@ bool QgsPostgresProvider::getGeometryDetails()
   }
   else
   {
-    detectedType = mRequestedGeomType == QGis::WKBUnknown ? "" : QgsPostgresConn::postgisWkbTypeName( mRequestedGeomType );
+    sql = QString( "SELECT %1 FROM %2 LIMIT 0" ).arg( quotedIdentifier( mGeometryColumn ), mQuery );
+    result = connectionRO()->PQexec( sql );
+    if ( PGRES_TUPLES_OK == result.PQresultStatus() )
+    {
+      sql = QString( "SELECT (SELECT t.typname FROM pg_type t WHERE oid = %1), upper(postgis_typmod_type(%2)), postgis_typmod_srid(%2)" )
+            .arg( QString::number( result.PQftype( 0 ) ), QString::number( result.PQfmod( 0 ) ) );
+      result = connectionRO()->PQexec( sql );
+      if ( result.PQntuples() == 1 )
+      {
+        geomColType  = result.PQgetvalue( 0, 0 );
+        detectedType = result.PQgetvalue( 0, 1 );
+        detectedSrid = result.PQgetvalue( 0, 2 );
+        if ( geomColType == "geometry" )
+          mSpatialColType = sctGeometry;
+        else if ( geomColType == "geography" )
+          mSpatialColType = sctGeography;
+        else if ( geomColType == "topogeometry" )
+          mSpatialColType = sctTopoGeometry;
+        else if ( geomColType == "pcpatch" )
+          mSpatialColType = sctPcPatch;
+        else
+        {
+          detectedType = mRequestedGeomType == QGis::WKBUnknown ? "" : QgsPostgresConn::postgisWkbTypeName( mRequestedGeomType );
+          detectedSrid = mRequestedSrid;
+        }
+      }
+      else
+      {
+        connectionRO()->PQexecNR( "COMMIT" );
+        detectedType = mRequestedGeomType == QGis::WKBUnknown ? "" : QgsPostgresConn::postgisWkbTypeName( mRequestedGeomType );
+      }
+    }
+    else
+    {
+      mValid = false;
+      return false;
+    }
   }
 
   mDetectedGeomType = QgsPostgresConn::wkbTypeFromPostgis( detectedType );

diff --git a/tests/src/python/test_provider_postgres.py b/tests/src/python/test_provider_postgres.py
@@ -59,6 +59,14 @@ def testDefaultValue(self):
         assert self.provider.defaultValue(1) == NULL
         assert self.provider.defaultValue(2) == '\'qgis\'::text'
 
+    def testQueryLayers(self):
+        def test_query(dbconn, query, key):
+            ql = QgsVectorLayer('%s srid=4326 table="%s" (geom) key=\'%s\' sql=' % (dbconn, query.replace('"', '\\"'), key), "testgeom", "postgres")
+            print query, key
+            assert(ql.isValid())
+
+        test_query(self.dbconn, '(SELECT NULL::integer "Id1", NULL::integer "Id2", NULL::geometry(Point, 4326) geom LIMIT 0)', '"Id1","Id2"')
+
     def testWkbTypes(self):
         def test_table(dbconn, table_name, wkt):
             vl = QgsVectorLayer('%s srid=4326 table="qgis_test".%s (geom) sql=' % (dbconn, table_name), "testgeom", "postgres")