Fix PG identity default value with long field names

Fix #51563
qgis · Jan 30, 2023 · fe5275b · fe5275b
1 parent f373f5b
commit fe5275b
Show file tree

Hide file tree

Showing 2 changed files with 21 additions and 12 deletions.
diff --git a/src/providers/postgres/qgspostgresprovider.cpp b/src/providers/postgres/qgspostgresprovider.cpp
@@ -1417,20 +1417,13 @@ bool QgsPostgresProvider::loadFields()
          && uniqueMap[tableoid][attnum]
          && defValMap[tableoid][attnum].isEmpty() )
     {
-      const QString seqName { mTableName + '_' + fieldName + QStringLiteral( "_seq" ) };
-      const QString seqSql = QStringLiteral( "SELECT c.oid::regclass "
-                                             "  FROM pg_class c "
-                                             "  LEFT JOIN pg_namespace n "
-                                             "    ON ( n.oid = c.relnamespace ) "
-                                             "  WHERE c.relkind = 'S' "
-                                             "    AND c.relname = %1 "
-                                             "    AND n.nspname = %2" )
-                             .arg( quotedValue( seqName ) )
-                             .arg( quotedValue( mSchemaName ) );
+      const QString seqSql = QStringLiteral( "SELECT pg_get_serial_sequence(%1, %2)" )
+                             .arg( quotedValue( mQuery ) )
+                             .arg( quotedValue( fieldName ) );
       QgsPostgresResult seqResult( connectionRO()->PQexec( seqSql ) );
       if ( seqResult.PQntuples() == 1 )
       {
-        defValMap[tableoid][attnum] = QStringLiteral( "nextval(%1::regclass)" ).arg( quotedValue( seqResult.PQgetvalue( 0, 0 ) ) );
+        defValMap[tableoid][attnum] = QStringLiteral( "nextval(%1)" ).arg( quotedValue( seqResult.PQgetvalue( 0, 0 ) ) );
       }
     }
 

diff --git a/tests/src/python/test_provider_postgres.py b/tests/src/python/test_provider_postgres.py
@@ -2604,7 +2604,7 @@ def testIdentityPk(self):
         feature.setGeometry(geom)
         self.assertTrue(vl.dataProvider().addFeature(feature))
 
-        self.assertEqual(vl.dataProvider().defaultValueClause(0), "nextval('qgis_test.b29560_gid_seq'::regclass)")
+        self.assertEqual(vl.dataProvider().defaultValueClause(0), "nextval('qgis_test.b29560_gid_seq')")
 
         del (vl)
 
@@ -2617,6 +2617,22 @@ def testIdentityPk(self):
         feature = next(vl.getFeatures())
         self.assertIsNotNone(feature.id())
 
+    def testIdentityLongFieldDefaultValue(self):
+        """Test issue GH #51563"""
+
+        self.execSQLCommand(
+            'DROP TABLE IF EXISTS qgis_test."test_IDENTIFIER_name_so_long_it_will_get_truncated" CASCADE')
+        self.execSQLCommand("""
+            CREATE TABLE qgis_test."test_IDENTIFIER_name_so_long_it_will_get_truncated"(
+                "test_IDENTIFIER_so_long_it_will_get_truncated" integer PRIMARY KEY GENERATED BY DEFAULT AS IDENTITY,
+                test_description text
+            );""")
+
+        vl = QgsVectorLayer(self.dbconn + ' sslmode=disable key=\'test_IDENTIFIER_so_long_it_will_get_truncated\' srid=0 table="qgis_test"."test_IDENTIFIER_name_so_long_it_will_get_truncated" () sql=', 'gh_51563_1', 'postgres')
+        self.assertTrue(vl.isValid())
+
+        self.assertEqual(vl.dataProvider().defaultValueClause(0), 'nextval(\'qgis_test."test_IDENTIFIER_name_so_long__test_IDENTIFIER_so_long_it_wi_seq"\')')
+
     def testEvalDefaultOnProviderSide(self):
         """Test issue GH #50168"""