本文整理汇总了Python中qgis.core.QgsVectorLayer.setFieldConstraint方法的典型用法代码示例。如果您正苦于以下问题:Python QgsVectorLayer.setFieldConstraint方法的具体用法?Python QgsVectorLayer.setFieldConstraint怎么用?Python QgsVectorLayer.setFieldConstraint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.QgsVectorLayer
的用法示例。
在下文中一共展示了QgsVectorLayer.setFieldConstraint方法的3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: testConstraintOverwrite
# 需要导入模块: from qgis.core import QgsVectorLayer [as 别名]
# 或者: from qgis.core.QgsVectorLayer import setFieldConstraint [as 别名]
def testConstraintOverwrite(self):
""" test that Postgres provider constraints can't be overwritten by vector layer method """
vl = QgsVectorLayer('%s table="qgis_test"."constraints" sql=' % (self.dbconn), "constraints", "postgres")
self.assertTrue(vl.isValid())
self.assertTrue(vl.dataProvider().fieldConstraints(0) & QgsFieldConstraints.ConstraintNotNull)
self.assertTrue(vl.fields().at(0).constraints().constraints() & QgsFieldConstraints.ConstraintNotNull)
# add a constraint at the layer level
vl.setFieldConstraint(0, QgsFieldConstraints.ConstraintUnique)
# should be no change at provider level
self.assertTrue(vl.dataProvider().fieldConstraints(0) & QgsFieldConstraints.ConstraintNotNull)
# but layer should still keep provider constraints...
self.assertTrue(vl.fields().at(0).constraints().constraints() & QgsFieldConstraints.ConstraintNotNull)
self.assertTrue(vl.fieldConstraints(0) & QgsFieldConstraints.ConstraintNotNull)
# ...in addition to layer level constraint
self.assertTrue(vl.fields().at(0).constraints().constraints() & QgsFieldConstraints.ConstraintUnique)
self.assertTrue(vl.fieldConstraints(0) & QgsFieldConstraints.ConstraintUnique)
示例2: testCreateFeature
# 需要导入模块: from qgis.core import QgsVectorLayer [as 别名]
# 或者: from qgis.core.QgsVectorLayer import setFieldConstraint [as 别名]
def testCreateFeature(self):
""" test creating a feature respecting defaults and constraints """
layer = QgsVectorLayer("Point?field=fldtxt:string&field=fldint:integer&field=flddbl:double",
"addfeat", "memory")
# add a bunch of features
f = QgsFeature()
f.setAttributes(["test", 123, 1.0])
f1 = QgsFeature(2)
f1.setAttributes(["test_1", 124, 1.1])
f2 = QgsFeature(3)
f2.setAttributes(["test_2", 125, 2.4])
f3 = QgsFeature(4)
f3.setAttributes(["test_3", 126, 1.7])
f4 = QgsFeature(5)
f4.setAttributes(["superpig", 127, 0.8])
self.assertTrue(layer.dataProvider().addFeatures([f, f1, f2, f3, f4]))
# no layer
self.assertFalse(QgsVectorLayerUtils.createFeature(None).isValid())
# basic tests
f = QgsVectorLayerUtils.createFeature(layer)
self.assertTrue(f.isValid())
self.assertEqual(f.fields(), layer.fields())
self.assertFalse(f.hasGeometry())
self.assertEqual(f.attributes(), [NULL, NULL, NULL])
# set geometry
g = QgsGeometry.fromPointXY(QgsPointXY(100, 200))
f = QgsVectorLayerUtils.createFeature(layer, g)
self.assertTrue(f.hasGeometry())
self.assertEqual(f.geometry().asWkt(), g.asWkt())
# using attribute map
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'a', 2: 6.0})
self.assertEqual(f.attributes(), ['a', NULL, 6.0])
# layer with default value expression
layer.setDefaultValueDefinition(2, QgsDefaultValue('3*4'))
f = QgsVectorLayerUtils.createFeature(layer)
self.assertEqual(f.attributes(), [NULL, NULL, 12])
# we do not expect the default value expression to take precedence over the attribute map
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'a', 2: 6.0})
self.assertEqual(f.attributes(), ['a', NULL, 6.0])
# layer with default value expression based on geometry
layer.setDefaultValueDefinition(2, QgsDefaultValue('3*$x'))
f = QgsVectorLayerUtils.createFeature(layer, g)
#adjusted so that input value and output feature are the same
self.assertEqual(f.attributes(), [NULL, NULL, 300.0])
layer.setDefaultValueDefinition(2, QgsDefaultValue(None))
# test with violated unique constraints
layer.setFieldConstraint(1, QgsFieldConstraints.ConstraintUnique)
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'test_1', 1: 123})
# since field 1 has Unique Constraint, it ignores value 123 that already has been set and sets to 128
self.assertEqual(f.attributes(), ['test_1', 128, NULL])
layer.setFieldConstraint(0, QgsFieldConstraints.ConstraintUnique)
# since field 0 and 1 already have values test_1 and 123, the output must be a new unique value
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'test_1', 1: 123})
self.assertEqual(f.attributes(), ['test_4', 128, NULL])
# test with violated unique constraints and default value expression providing unique value
layer.setDefaultValueDefinition(1, QgsDefaultValue('130'))
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'test_1', 1: 123})
# since field 1 has Unique Constraint, it ignores value 123 that already has been set and adds the default value
self.assertEqual(f.attributes(), ['test_4', 130, NULL])
# fallback: test with violated unique constraints and default value expression providing already existing value
# add the feature with the default value:
self.assertTrue(layer.dataProvider().addFeatures([f]))
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'test_1', 1: 123})
# since field 1 has Unique Constraint, it ignores value 123 that already has been set and adds the default value
# and since the default value providing an already existing value (130) it generates a unique value (next int: 131)
self.assertEqual(f.attributes(), ['test_5', 131, NULL])
layer.setDefaultValueDefinition(1, QgsDefaultValue(None))
# test with manually correct unique constraint
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'test_1', 1: 132})
self.assertEqual(f.attributes(), ['test_5', 132, NULL])
""" test creating a feature respecting unique values of postgres provider """
layer = QgsVectorLayer("Point?field=fldtxt:string&field=fldint:integer&field=flddbl:double",
"addfeat", "memory")
# init connection string
dbconn = 'dbname=\'qgis_test\''
if 'QGIS_PGTEST_DB' in os.environ:
dbconn = os.environ['QGIS_PGTEST_DB']
# create a vector layer
pg_layer = QgsVectorLayer('{} table="qgis_test"."authors" sql='.format(dbconn), "authors", "postgres")
self.assertTrue(pg_layer.isValid())
# check the default clause
default_clause = 'nextval(\'qgis_test.authors_pk_seq\'::regclass)'
self.assertEqual(pg_layer.dataProvider().defaultValueClause(0), default_clause)
# though default_clause is after the first create not unique (until save), it should fill up all the features with it
pg_layer.startEditing()
f = QgsVectorLayerUtils.createFeature(pg_layer)
self.assertEqual(f.attributes(), [default_clause, NULL])
self.assertTrue(pg_layer.addFeatures([f]))
#.........这里部分代码省略.........
示例3: testCreateFeature
# 需要导入模块: from qgis.core import QgsVectorLayer [as 别名]
# 或者: from qgis.core.QgsVectorLayer import setFieldConstraint [as 别名]
def testCreateFeature(self):
""" test creating a feature respecting defaults and constraints """
layer = QgsVectorLayer("Point?field=fldtxt:string&field=fldint:integer&field=flddbl:double",
"addfeat", "memory")
# add a bunch of features
f = QgsFeature()
f.setAttributes(["test", 123, 1.0])
f1 = QgsFeature(2)
f1.setAttributes(["test_1", 124, 1.1])
f2 = QgsFeature(3)
f2.setAttributes(["test_2", 125, 2.4])
f3 = QgsFeature(4)
f3.setAttributes(["test_3", 126, 1.7])
f4 = QgsFeature(5)
f4.setAttributes(["superpig", 127, 0.8])
self.assertTrue(layer.dataProvider().addFeatures([f, f1, f2, f3, f4]))
# no layer
self.assertFalse(QgsVectorLayerUtils.createFeature(None).isValid())
# basic tests
f = QgsVectorLayerUtils.createFeature(layer)
self.assertTrue(f.isValid())
self.assertEqual(f.fields(), layer.fields())
self.assertFalse(f.hasGeometry())
self.assertEqual(f.attributes(), [NULL, NULL, NULL])
# set geometry
g = QgsGeometry.fromPointXY(QgsPointXY(100, 200))
f = QgsVectorLayerUtils.createFeature(layer, g)
self.assertTrue(f.hasGeometry())
self.assertEqual(f.geometry().asWkt(), g.asWkt())
# using attribute map
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'a', 2: 6.0})
self.assertEqual(f.attributes(), ['a', NULL, 6.0])
# layer with default value expression
layer.setDefaultValueDefinition(2, QgsDefaultValue('3*4'))
f = QgsVectorLayerUtils.createFeature(layer)
self.assertEqual(f.attributes(), [NULL, NULL, 12])
# we do not expect the default value expression to take precedence over the attribute map
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'a', 2: 6.0})
self.assertEqual(f.attributes(), ['a', NULL, 6.0])
# layer with default value expression based on geometry
layer.setDefaultValueDefinition(2, QgsDefaultValue('3*$x'))
f = QgsVectorLayerUtils.createFeature(layer, g)
#adjusted so that input value and output feature are the same
self.assertEqual(f.attributes(), [NULL, NULL, 300.0])
layer.setDefaultValueDefinition(2, QgsDefaultValue(None))
# test with violated unique constraints
layer.setFieldConstraint(1, QgsFieldConstraints.ConstraintUnique)
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'test_1', 1: 123})
# since field 1 has Unique Constraint, it ignores value 123 that already has been set and sets to 128
self.assertEqual(f.attributes(), ['test_1', 128, NULL])
layer.setFieldConstraint(0, QgsFieldConstraints.ConstraintUnique)
# since field 0 and 1 already have values test_1 and 123, the output must be a new unique value
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'test_1', 1: 123})
self.assertEqual(f.attributes(), ['test_4', 128, NULL])
# test with violated unique constraints and default value expression providing unique value
layer.setDefaultValueDefinition(1, QgsDefaultValue('130'))
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'test_1', 1: 123})
# since field 1 has Unique Constraint, it ignores value 123 that already has been set and adds the default value
self.assertEqual(f.attributes(), ['test_4', 130, NULL])
# fallback: test with violated unique constraints and default value expression providing already existing value
# add the feature with the default value:
self.assertTrue(layer.dataProvider().addFeatures([f]))
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'test_1', 1: 123})
# since field 1 has Unique Constraint, it ignores value 123 that already has been set and adds the default value
# and since the default value providing an already existing value (130) it generates a unique value (next int: 131)
self.assertEqual(f.attributes(), ['test_5', 131, NULL])
layer.setDefaultValueDefinition(1, QgsDefaultValue(None))
# test with manually correct unique constraint
f = QgsVectorLayerUtils.createFeature(layer, attributes={0: 'test_1', 1: 132})
self.assertEqual(f.attributes(), ['test_5', 132, NULL])