Class: QgsVectorLayerJoinInfo¶

class qgis.core.QgsVectorLayerJoinInfo¶

Bases: sip.wrapper

Constructor for QgsVectorLayerJoinInfo.

QgsVectorLayerJoinInfo(QgsVectorLayerJoinInfo)

Defines left outer join from our vector layer to some other vector layer. The join is done based on [our layer].targetField = [join layer].joinField

New in version 3.0: Enums

Methods

`extractJoinedFeature`	Extract the join feature from the target feature for the current join layer information.
`hasCascadedDelete`	Returns whether a feature deleted on the target layer has to impact the joined layer by deleting the corresponding joined feature.
`hasSubset`	Returns true if blacklisted fields is not empty or if a subset of names has been set.
`hasUpsertOnEdit`	Returns whether a feature created on the target layer has to impact the joined layer by creating a new feature if necessary.
`isDynamicFormEnabled`	Returns whether the form has to be dynamically updated with joined fields when a feature is being created in the target layer.
`isEditable`	Returns whether joined fields may be edited through the form of the target layer.
`isUsingMemoryCache`	Returns whether values from the joined layer should be cached in memory to speed up lookups
`joinFieldName`	Returns name of the field of joined layer that will be used for join
`joinFieldNamesBlackList`	Returns the list of fields to ignore.
`joinFieldNamesSubset`	Returns the list of field names to use for joining considering blacklisted fields and subset.
`joinLayer`	Returns joined layer (may be null if the reference was set by layer ID and not resolved yet)
`joinLayerId`	ID of the joined layer - may be used to resolve reference to the joined layer
`prefix`	Returns prefix of fields from the joined layer.
`prefixedFieldName`	Returns the prefixed name of the field.
`setCascadedDelete`	Sets whether a feature deleted on the target layer has to impact the joined layer by deleting the corresponding joined feature.
`setDynamicFormEnabled`	Sets whether the form has to be dynamically updated with joined fields when a feature is being created in the target layer.
`setEditable`	Sets whether the form of the target layer allows editing joined fields.
`setJoinFieldName`	Sets name of the field of joined layer that will be used for join
`setJoinFieldNamesBlackList`	Sets a list of fields to ignore whatever happens.
`setJoinFieldNamesSubset`	Set subset of fields to be used from joined layer.
`setJoinLayer`	Sets weak reference to the joined layer
`setJoinLayerId`	Sets ID of the joined layer.
`setPrefix`	Sets prefix of fields from the joined layer.
`setTargetFieldName`	Sets name of the field of our layer that will be used for join
`setUpsertOnEdit`	Sets whether a feature created on the target layer has to impact the joined layer by creating a new feature if necessary.
`setUsingMemoryCache`	Sets whether values from the joined layer should be cached in memory to speed up lookups
`targetFieldName`	Returns name of the field of our layer that will be used for join

Signals

Attributes

extractJoinedFeature(self, feature: QgsFeature) → QgsFeature¶

Extract the join feature from the target feature for the current join layer information.

Parameters: feature – A feature from the target layer
Returns: the corresponding joined feature

New in version 3.0.

hasCascadedDelete(self) → bool¶: Returns whether a feature deleted on the target layer has to impact the joined layer by deleting the corresponding joined feature.

New in version 3.0.

hasSubset(self, blacklisted: bool = True) → bool¶: Returns true if blacklisted fields is not empty or if a subset of names has been set.

New in version 3.0.

hasUpsertOnEdit(self) → bool¶: Returns whether a feature created on the target layer has to impact the joined layer by creating a new feature if necessary.

New in version 3.0.

isDynamicFormEnabled(self) → bool¶: Returns whether the form has to be dynamically updated with joined fields when a feature is being created in the target layer.

New in version 3.0.

isEditable(self) → bool¶: Returns whether joined fields may be edited through the form of the target layer.

New in version 3.0.

isUsingMemoryCache(self) → bool¶: Returns whether values from the joined layer should be cached in memory to speed up lookups

joinFieldName(self) → str¶: Returns name of the field of joined layer that will be used for join

joinFieldNamesBlackList(self) → List[str]¶: Returns the list of fields to ignore.

New in version 3.0.

joinFieldNamesSubset(info: QgsVectorLayerJoinInfo, blacklisted: bool = True) → List[str]¶

Returns the list of field names to use for joining considering blacklisted fields and subset.

New in version 3.0.

joinFieldNamesSubset(self) -> List[str] Gets subset of fields to be used from joined layer. All fields will be used if null is returned.

New in version 2.6.

joinLayer(self) → QgsVectorLayer¶: Returns joined layer (may be null if the reference was set by layer ID and not resolved yet)

joinLayerId(self) → str¶: ID of the joined layer - may be used to resolve reference to the joined layer

prefix(self) → str¶: Returns prefix of fields from the joined layer. If null, joined layer’s name will be used.

prefixedFieldName(self, field: QgsField) → str¶

Returns the prefixed name of the field.

Parameters: field – the field
Returns: the prefixed name of the field

New in version 3.0.

setCascadedDelete(self, enabled: bool)¶: Sets whether a feature deleted on the target layer has to impact the joined layer by deleting the corresponding joined feature.

New in version 3.0.

setDynamicFormEnabled(self, enabled: bool)¶: Sets whether the form has to be dynamically updated with joined fields when a feature is being created in the target layer.

New in version 3.0.

setEditable(self, enabled: bool)¶: Sets whether the form of the target layer allows editing joined fields.

New in version 3.0.

setJoinFieldName(self, fieldName: str)¶: Sets name of the field of joined layer that will be used for join

setJoinFieldNamesBlackList(self, blackList: Iterable[str])¶: Sets a list of fields to ignore whatever happens.

New in version 3.0.

setJoinFieldNamesSubset(self, fieldNamesSubset: Iterable[str])¶: Set subset of fields to be used from joined layer. Takes ownership of the passed pointer. Null pointer tells to use all fields.

New in version 2.6.

setJoinLayer(self, layer: QgsVectorLayer)¶: Sets weak reference to the joined layer

setJoinLayerId(self, layerId: str)¶: Sets ID of the joined layer. It will need to be overwritten by setJoinLayer() to a reference to real layer

setPrefix(self, prefix: str)¶: Sets prefix of fields from the joined layer. If null, joined layer’s name will be used.

setTargetFieldName(self, fieldName: str)¶: Sets name of the field of our layer that will be used for join

setUpsertOnEdit(self, enabled: bool)¶: Sets whether a feature created on the target layer has to impact the joined layer by creating a new feature if necessary.

New in version 3.0.

setUsingMemoryCache(self, enabled: bool)¶: Sets whether values from the joined layer should be cached in memory to speed up lookups

targetFieldName(self) → str¶: Returns name of the field of our layer that will be used for join