fix discovering relation when a table has relation with several layers

qgis · Jan 27, 2021 · c75e160 · c75e160
1 parent 1047110
commit c75e160
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Showing 3 changed files with 52 additions and 1 deletion.
diff --git a/src/providers/postgres/qgspostgresprovider.cpp b/src/providers/postgres/qgspostgresprovider.cpp
@@ -4989,6 +4989,7 @@ QList<QgsRelation> QgsPostgresProvider::discoverRelations( const QgsVectorLayer
   }
 
   int nbFound = 0;
+  QList<QString> refTableFound;
   for ( int row = 0; row < sqlResult.PQntuples(); ++row )
   {
     const QString name = sqlResult.PQgetvalue( row, 0 );
@@ -5006,7 +5007,7 @@ QList<QgsRelation> QgsPostgresProvider::discoverRelations( const QgsVectorLayer
     }
     const QString refColumn = sqlResult.PQgetvalue( row, 4 );
     const QString position = sqlResult.PQgetvalue( row, 5 );
-    if ( ( position == QLatin1String( "1" ) ) || ( nbFound == 0 ) )
+    if ( ( position == QLatin1String( "1" ) ) || ( nbFound == 0 ) || ( !refTableFound.contains( refTable ) ) )
     {
       // first reference field => try to find if we have layers for the referenced table
       const QList<QgsVectorLayer *> foundLayers = searchLayers( layers, mUri.connectionInfo( false ), refSchema, refTable );
@@ -5023,6 +5024,7 @@ QList<QgsRelation> QgsPostgresProvider::discoverRelations( const QgsVectorLayer
         {
           result.append( relation );
           ++nbFound;
+          refTableFound.append( refTable );
         }
         else
         {

diff --git a/tests/src/python/test_provider_postgres.py b/tests/src/python/test_provider_postgres.py
@@ -2286,6 +2286,31 @@ def testInvalidLayerDiscoverRelations(self):
         self.assertFalse(vl.isValid())
         self.assertEqual(vl.dataProvider().discoverRelations(vl, []), [])
 
+    def testValidLayerDiscoverRelations(self):
+        vl = QgsVectorLayer(
+            self.dbconn +
+            ' sslmode=disable key=\'pk\' checkPrimaryKeyUnicity=\'1\' table="qgis_test"."referencing_layer"',
+            'referencing_layer', 'postgres')
+        vls = [
+            QgsVectorLayer(
+                self.dbconn +
+                ' sslmode=disable key=\'pk_ref_1\' checkPrimaryKeyUnicity=\'1\' table="qgis_test"."referenced_layer_1"',
+                'referenced_layer_1', 'postgres'),
+            QgsVectorLayer(
+                self.dbconn +
+                ' sslmode=disable key=\'pk_ref_2\' checkPrimaryKeyUnicity=\'1\' table="qgis_test"."referenced_layer_2"',
+                'referenced_layer_2', 'postgres'),
+            vl
+        ]
+
+        for lyr in vls:
+            self.assertTrue(lyr.isValid())
+            QgsProject.instance().addMapLayer(lyr)
+        relations = vl.dataProvider().discoverRelations(vl, vls)
+        self.assertEqual(len(relations), 2)
+        for i, r in enumerate(relations):
+            self.assertEqual(r.referencedLayer(), vls[i])
+
     def testCheckTidPkOnViews(self):
         """Test vector layer based on a view with `ctid` as a key"""
 

diff --git a/tests/testdata/provider/testdata_pg.sql b/tests/testdata/provider/testdata_pg.sql
@@ -721,3 +721,27 @@ CREATE TABLE IF NOT EXISTS "test_check_constraint" (
 INSERT INTO test_check_constraint (geom, i_will_fail_on_no_name)
 VALUES ('SRID=4326;POINT(9 45)'::geometry, 'I have a name'), ('SRID=4326;POINT(10 46)'::geometry, 'I have a name too');
 
+---------------------------------------------
+--
+-- Tables to check tables relation in project
+--
+
+CREATE TABLE qgis_test.referenced_layer_1(
+  pk_ref_1 serial primary key 
+);
+
+CREATE TABLE qgis_test.referenced_layer_2(
+  pk_ref_2 serial primary key 
+);
+
+CREATE TABLE qgis_test.referencing_layer(
+  pk serial primary key,
+  fk_ref_1 integer,
+  fk_ref_2 integer,
+    CONSTRAINT fk_ref_1
+      FOREIGN KEY(fk_ref_1) 
+    REFERENCES qgis_test.referenced_layer_1(pk_ref_1),
+    CONSTRAINT fk_ref_2
+      FOREIGN KEY(fk_ref_2) 
+    REFERENCES qgis_test.referenced_layer_2(pk_ref_2)
+);