本文整理汇总了Python中qgis.core.QgsVectorLayerJoinInfo.setUsingMemoryCache方法的典型用法代码示例。如果您正苦于以下问题：Python QgsVectorLayerJoinInfo.setUsingMemoryCache方法的具体用法？Python QgsVectorLayerJoinInfo.setUsingMemoryCache怎么用？Python QgsVectorLayerJoinInfo.setUsingMemoryCache使用的例子？那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在类qgis.core.QgsVectorLayerJoinInfo的用法示例。
在下文中一共展示了QgsVectorLayerJoinInfo.setUsingMemoryCache方法的2个代码示例，这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞，您的评价将有助于系统推荐出更棒的Python代码示例。
示例1: test_JoinUsingExpression2
# 需要导入模块: from qgis.core import QgsVectorLayerJoinInfo [as 别名]
# 或者: from qgis.core.QgsVectorLayerJoinInfo import setUsingMemoryCache [as 别名]
def test_JoinUsingExpression2(self):
""" test joining a layer using a virtual field (the other way!) """
joinLayer = QgsVectorLayer(
"Point?field=x:string&field=y:integer&field=z:integer",
"joinlayer", "memory")
pr = joinLayer.dataProvider()
f1 = QgsFeature()
f1.setAttributes(["foo", 246, 321])
f2 = QgsFeature()
f2.setAttributes(["bar", 456, 654])
self.assertTrue(pr.addFeatures([f1, f2]))
joinLayer.addExpressionField('"y"/2', QgsField('exp1', QVariant.LongLong))
layer = QgsVectorLayer("Point?field=fldtxt:string&field=fldint:integer",
"addfeat", "memory")
pr = layer.dataProvider()
f = QgsFeature()
f.setAttributes(["test", 123])
self.assertTrue(pr.addFeatures([f]))
QgsProject.instance().addMapLayers([layer, joinLayer])
join = QgsVectorLayerJoinInfo()
join.setTargetFieldName("fldint")
join.setJoinLayer(joinLayer)
join.setJoinFieldName("exp1")
join.setUsingMemoryCache(True)
layer.addJoin(join)
f = QgsFeature()
fi = layer.getFeatures()
self.assertTrue(fi.nextFeature(f))
attrs = f.attributes()
self.assertEqual(attrs[0], "test")
self.assertEqual(attrs[1], 123)
self.assertEqual(attrs[2], "foo")
self.assertEqual(attrs[3], 246)
self.assertEqual(attrs[4], 321)
self.assertFalse(fi.nextFeature(f))
QgsProject.instance().removeMapLayers([layer.id(), joinLayer.id()])示例2: test_JoinUsingFeatureRequestExpression
# 需要导入模块: from qgis.core import QgsVectorLayerJoinInfo [as 别名]
# 或者: from qgis.core.QgsVectorLayerJoinInfo import setUsingMemoryCache [as 别名]
def test_JoinUsingFeatureRequestExpression(self):
""" test requesting features using a filter expression which requires joined columns """
joinLayer = QgsVectorLayer(
"Point?field=x:string&field=y:integer&field=z:integer",
"joinlayer", "memory")
pr = joinLayer.dataProvider()
f1 = QgsFeature()
f1.setAttributes(["foo", 123, 321])
f2 = QgsFeature()
f2.setAttributes(["bar", 124, 654])
self.assertTrue(pr.addFeatures([f1, f2]))
layer = QgsVectorLayer("Point?field=fldtxt:string&field=fldint:integer",
"addfeat", "memory")
pr = layer.dataProvider()
f1 = QgsFeature()
f1.setAttributes(["test", 123])
f2 = QgsFeature()
f2.setAttributes(["test", 124])
self.assertTrue(pr.addFeatures([f1, f2]))
QgsProject.instance().addMapLayers([layer, joinLayer])
join = QgsVectorLayerJoinInfo()
join.setTargetFieldName("fldint")
join.setJoinLayer(joinLayer)
join.setJoinFieldName("y")
join.setUsingMemoryCache(True)
layer.addJoin(join)
f = QgsFeature()
fi = layer.getFeatures(QgsFeatureRequest().setFlags(QgsFeatureRequest.SubsetOfAttributes).setFilterExpression('joinlayer_z=654'))
self.assertTrue(fi.nextFeature(f))
self.assertEqual(f['fldint'], 124)
self.assertEqual(f['joinlayer_z'], 654)
QgsProject.instance().removeMapLayers([layer.id(), joinLayer.id()])