def joinLayer(self, targetlayer, pkfield, sourcelayer, fkfield):
"""
Join the results of the SQL Server query to the pg layer
"""
joinInfo = QgsVectorLayerJoinInfo()
# Backward compatbility QGIS3=>2
if qversion == 3:
joinInfo.setTargetFieldName(pkfield)
joinInfo.setJoinLayer(sourcelayer)
joinInfo.setJoinFieldName(fkfield)
joinInfo.setUsingMemoryCache(True)
else: # QGIS 2
joinInfo.targetFieldName = pkfield
joinInfo.joinLayerId = sourcelayer.id()
joinInfo.joinFieldName = fkfield
joinInfo.memoryCache = True
targetlayer.addJoin(joinInfo)
targetlayer.updateFields()
return targetlayer
def execute_layers_join(layer, layer_field, column_header, fk_layer,
fk_field):
"""
Joins two layers with specified field.
:param layer: The destination layer of the merge.
:type layer: QgsVectorLayer
:param layer_field: The source layer of the merge.
:type layer_field: String
:param fk_layer: The foreign key layer object.
:type fk_layer: QgsVectorLayer
:param fk_field: The foreign key layer field name.
:type fk_field: String
:return:
:rtype:
"""
join = QgsVectorLayerJoinInfo()
join.joinLayerId = fk_layer.id()
join.joinFieldName = 'id'
join.setJoinFieldNamesSubset([fk_field])
join.targetFieldName = layer_field
join.memoryCache = True
join.prefix = '{} '.format(column_header)
layer.addJoin(join)
