Class: QgsVectorDataProvider¶

Base class for vector data providers.

Data providers abstract the retrieval and writing (where supported) of feature and attribute information from a spatial datasource.

Note

This is an abstract class, with methods which must be implemented by a subclass.

The following methods must be implemented: QgsDataProvider.crs(), QgsDataProvider.description(), QgsDataProvider.extent(), featureSource(), QgsDataProvider.isValid(), QgsDataProvider.name()

Class Hierarchy¶

Base classes¶

`QgsDataProvider`	Abstract base class for spatial data provider implementations.
QObject
`QgsFeatureSink`	An interface for objects which accept features via addFeature(s) methods.
`QgsFeatureSource`	An interface for objects which provide features via a getFeatures method.

Enums

`Capability`	alias of `VectorProviderCapability`
`FeatureCountState`	Enumeration of feature count states

Abstract Methods

`featureCount`	Number of features in the layer
`featureSource`	Returns feature source object that can be used for querying provider's data.
`fields`	Returns the fields associated with this data provider.
`getFeatures`	Query the provider for features specified in request.
`wkbType`	Returns the geometry type which is returned by this layer

Methods

`capabilitiesString`	Returns the above in friendly format.
`clearErrors`	Clear recorded errors
`clearMinMaxCache`	Invalidates the min/max cache.
`convertToProviderType`	Converts the geometry to the provider type if possible / necessary
`encoding`	Returns the encoding which is used for accessing data.
`errors`	Gets recorded errors
`fieldConstraints`	Returns any constraints which are present at the provider for a specified field index.
`fieldNameIndex`	Returns the index of a field name or -1 if the field does not exist
`fieldNameMap`	Returns a map where the key is the name of the field and the value is its index
`fillMinMaxCache`	Populates the cache of minimum and maximum attribute values.
`hasErrors`	Provider has errors to report
`nativeTypes`	Returns the names of the supported types
`palAttributeIndexNames`	Returns list of indexes to names for `QgsPalLabeling` fix
`pushError`	Push a notification about errors that happened in this providers scope.
`setNativeTypes`	Set the list of native types supported by this provider.
`supportedType`	check if provider supports type of field
`textEncoding`	Gets this providers encoding

Virtual Methods

In PyQGIS, only methods marked as virtual can be safely overridden in a Python subclass of QgsVectorDataProvider. See the FAQ for more details.

`addAttributes`	Adds new attributes to the provider.
`aggregate`	Calculates an aggregated value from the layer's features.
`attributeEditCapabilities`	Returns the provider's supported attribute editing capabilities.
`attributeIndexes`	Returns list of indexes to fetch all attributes in `nextFeature()`
`cancelReload`	Cancels the current reloading of data.
`capabilities`	Returns flags containing the supported capabilities note, some capabilities may change depending on whether a spatial filter is active on this provider, so it may be prudent to check this value per intended operation.
`changeAttributeValues`	Changes attribute values of existing features.
`changeFeatures`	Changes attribute values and geometries of existing features.
`changeGeometryValues`	Changes geometries of existing features
`createAttributeIndex`	Create an attribute index on the datasource
`createLabeling`	Creates labeling settings, using provider backend specific information.
`createRenderer`	Creates a new vector layer feature renderer, using provider backend specific information.
`createSpatialIndex`	Creates a spatial index on the datasource (if supported by the provider type).
`dataComment`	Returns a short comment for the data that this provider is providing access to (e.g. the comment for postgres table).
`defaultValue`	Returns any literal default values which are present at the provider for a specified field index.
`defaultValueClause`	Returns any default value clauses which are present at the provider for a specified field index.
`deleteAttributes`	Deletes existing attributes from the provider.
`deleteFeatures`	Deletes one or more features from the provider.
`dependencies`	Gets the list of layer ids on which this layer depends.
`discoverRelations`	Discover the available relations with the given layers.
`doesStrictFeatureTypeCheck`	Returns `True` if the provider is strict about the type of inserted features (e.g. no multipolygon in a polygon layer).
`empty`	Returns `True` if the layer does not contain any feature.
`enumValues`	Returns the possible enum values of an attribute.
`forceReload`
`geometryColumnName`	Returns the name of the column storing geometry, if applicable.
`handlePostCloneOperations`	Handles any post-clone operations required after this vector data provider was cloned from the source provider.
`hasFeatures`	Will always return FeatureAvailability.FeaturesAvailable or FeatureAvailability.NoFeaturesAvailable.
`hasMetadata`	Returns `True` if the data source has metadata, `False` otherwise.
`isSqlQuery`	Returns `True` if the layer is a query (SQL) layer.
`maximumValue`	Returns the maximum value of an attribute
`metadata`	Gets metadata, dependent on the provider type, that will be display in the metadata tab of the layer properties.
`minimumValue`	Returns the minimum value of an attribute
`pkAttributeIndexes`	Returns list of indexes of fields that make up the primary key
`renameAttributes`	Renames existing attributes.
`setEncoding`	Set encoding used for accessing data from layer.
`skipConstraintCheck`	Returns `True` if a constraint check should be skipped for a specified field (e.g., if the value returned by `defaultValue()` is trusted implicitly.
`storageType`	Returns the permanent storage type for this layer as a friendly name.
`transaction`	Returns the transaction this data provider is included in, if any.
`translateMetadataKey`	Gets the translated metadata key.
`translateMetadataValue`	Gets the translated metadata value.
`truncate`	Removes all features from the layer.
`uniqueStringsMatching`	Returns unique string values of an attribute which contain a specified subset string.
`vectorLayerTypeFlags`	Returns the vector layer type flags.

Static Methods

`availableEncodings`	Returns a list of available encodings
`convertValue`	Convert value to type

Signals

raiseError

Signals an error in this provider

class qgis.core.QgsVectorDataProvider[source]¶

Bases: QgsDataProvider, QgsFeatureSink, QgsFeatureSource

__init__(uri: str | None = '', providerOptions: QgsDataProvider.ProviderOptions = QgsDataProvider.ProviderOptions(), flags: Qgis.DataProviderReadFlags | Qgis.DataProviderReadFlag = Qgis.DataProviderReadFlags())

Constructor for a vector data provider.

The uri argument specifies the uniform resource locator (URI) for the associated dataset.

Additional creation options are specified within the options value and since QGIS 3.16 creation flags are specified within the flags value.

Parameters:

uri (Optional[str] = '')
providerOptions (QgsDataProvider.ProviderOptions = QgsDataProvider.ProviderOptions())
flags (Union[Qgis.DataProviderReadFlags, Qgis.DataProviderReadFlag] = Qgis.DataProviderReadFlags())

Capabilities¶: alias of VectorProviderCapabilities

Capability¶: alias of VectorProviderCapability

class FeatureCountState(*values)¶

Bases: IntEnum

Enumeration of feature count states

Added in version 3.20.

Uncounted: Feature count not yet computed
UnknownCount: Provider returned an unknown feature count

class NativeType(typeDesc: str | None, typeName: str | None, type: QMetaType.Type, minLen: int = 0, maxLen: int = 0, minPrec: int = 0, maxPrec: int = 0, subType: QMetaType.Type = QMetaType.Type.UnknownType)¶

class NativeType(typeDesc: str | None, typeName: str | None, type: QVariant.Type, minLen: int = 0, maxLen: int = 0, minPrec: int = 0, maxPrec: int = 0, subType: QVariant.Type = QVariant.Type.Invalid)

class NativeType(a0: QgsVectorDataProvider.NativeType)

Bases: object

mMaxLen¶

mMaxPrec¶

mMinLen¶

mMinPrec¶

mSubType¶

mType¶

mTypeDesc¶

mTypeName¶

virtual addAttributes(self, attributes: Any) → bool[source]¶

Adds new attributes to the provider. Returns True in case of success and False in case of failure. If attributes are added using this method then QgsVectorLayer.updateFields() must be called manually to ensure that the layer’s field are correctly reported.

Parameters:: attributes (Any)
Return type:: bool

virtual aggregate(self, aggregate: Qgis.Aggregate, index: int, parameters: QgsAggregateCalculator.AggregateParameters, context: QgsExpressionContext | None, fids: Any | None = None)[source]¶

Calculates an aggregated value from the layer’s features. The base implementation does nothing, but subclasses can override this method to handoff calculation of aggregates to the provider.

Parameters:

aggregate (Qgis.Aggregate) – aggregate to calculate
index (int) – the index of the attribute to calculate aggregate over
parameters (QgsAggregateCalculator.AggregateParameters) – parameters controlling aggregate calculation
context (Optional[QgsExpressionContext]) – expression context for filter
ok – will be set to True if calculation was successfully performed by the data provider
fids (Optional[Any] = None) -> (Any) – list of fids to filter, otherwise will use all fids

Returns:

calculated aggregate value

virtual attributeEditCapabilities(self) → Qgis.VectorDataProviderAttributeEditCapabilities[source]¶

Returns the provider’s supported attribute editing capabilities.

See also

capabilities()

Added in version 3.32.

Return type:: Qgis.VectorDataProviderAttributeEditCapabilities

virtual attributeIndexes(self) → List[int][source]¶

Returns list of indexes to fetch all attributes in nextFeature()

Return type:: List[int]

static availableEncodings() → List[str][source]¶

Returns a list of available encodings

Return type:: List[str]

virtual cancelReload(self) → bool[source]¶

Cancels the current reloading of data.

Return type:: bool
Returns:: True if the reloading has been correctly interrupted, False otherwise

See also

reloadData()

Added in version 3.2.

virtual capabilities(self) → Qgis.VectorProviderCapabilities[source]¶

Returns flags containing the supported capabilities note, some capabilities may change depending on whether a spatial filter is active on this provider, so it may be prudent to check this value per intended operation.

See also

attributeEditCapabilities()

Return type:: Qgis.VectorProviderCapabilities

capabilitiesString(self) → str[source]¶

Returns the above in friendly format.

Return type:: str

virtual changeAttributeValues(self, attr_map: Any) → bool[source]¶

Changes attribute values of existing features. This should succeed if the provider reports the ChangeAttributeValues capability. The method returns False if the provider does not have ChangeAttributeValues capability or if any of the changes could not be successfully applied.

Parameters:: attr_map (Any) – a map containing changed attributes
Return type:: bool
Returns:: True in case of success and False in case of failure

virtual changeFeatures(self, attr_map: Any, geometry_map: Any) → bool[source]¶

Changes attribute values and geometries of existing features. This should succeed if the provider reports both the ChangeAttributeValues and ChangeGeometries capabilities. Providers which report the ChangeFeatures capability implement an optimised version of this method.

Parameters:

attr_map (Any) – a map containing changed attributes
geometry_map (Any) – A QgsGeometryMap whose index contains the feature IDs that will have their geometries changed. The second map parameter being the new geometries themselves

Return type:

bool

Returns:

True in case of success and False in case of failure

virtual changeGeometryValues(self, geometry_map: Any) → bool[source]¶

Changes geometries of existing features

Parameters:: geometry_map (Any) – A QgsGeometryMap whose index contains the feature IDs that will have their geometries changed. The second map parameter being the new geometries themselves
Return type:: bool
Returns:: True in case of success and False in case of failure

clearErrors(self)[source]¶: Clear recorded errors

clearMinMaxCache(self)[source]¶: Invalidates the min/max cache. This will force the provider to recalculate the cache the next time it is requested.

convertToProviderType(self, geom: QgsGeometry) → QgsGeometry[source]¶

Converts the geometry to the provider type if possible / necessary

Return type:: QgsGeometry
Returns:: the converted geometry or None if no conversion was necessary or possible

Note

The default implementation simply calls the static version of this function.

Parameters:: geom (QgsGeometry)

convertToProviderType(geometry: QgsGeometry, providerGeometryType: Qgis.WkbType) → QgsGeometry[source]

Converts the geometry to the provider geometry type providerGeometryType if possible / necessary

Return type:: QgsGeometry
Returns:: the converted geometry or None if no conversion was necessary or possible

Added in version 3.34.

Parameters:

geometry (QgsGeometry)
providerGeometryType (Qgis.WkbType)

static convertValue(type: QMetaType.Type, value: str | None) → Any[source]¶

Convert value to type

Parameters:

type (QMetaType.Type)
value (Optional[str])

Return type:

Any

static convertValue(type: QVariant.Type, value: str | None) → Any[source]

Convert value to type

Deprecated since version 3.38: Use the method with a QMetaType.Type argument instead.

Parameters:

type (QVariant.Type)
value (Optional[str])

Return type:

Any

virtual createAttributeIndex(self, field: int) → bool[source]¶

Create an attribute index on the datasource

Parameters:: field (int)
Return type:: bool

virtual createLabeling(self, configuration: Dict[str, Any] = {}) → QgsAbstractVectorLayerLabeling | None[source]¶

Creates labeling settings, using provider backend specific information.

The configuration map can be used to pass provider-specific configuration maps to the provider to allow customization of the returned labeling object. Support and format of configuration varies by provider.

When called with an empty configuration map the provider’s default labeling settings will be returned.

This method returns a new labeling settings and the caller takes ownership of the returned object.

Only providers which report the CreateLabeling capability will return labeling settings. Other providers will return None.

Added in version 3.6.

Parameters:: configuration (Dict[str, Any] = {})
Return type:: Optional[QgsAbstractVectorLayerLabeling]

virtual createRenderer(self, configuration: Dict[str, Any] = {}) → QgsFeatureRenderer | None[source]¶

Creates a new vector layer feature renderer, using provider backend specific information.

The configuration map can be used to pass provider-specific configuration maps to the provider to allow customization of the returned renderer. Support and format of configuration varies by provider.

When called with an empty configuration map the provider’s default renderer will be returned.

This method returns a new renderer and the caller takes ownership of the returned object.

Only providers which report the CreateRenderer capability will return a feature renderer. Other providers will return None.

Added in version 3.2.

Parameters:: configuration (Dict[str, Any] = {})
Return type:: Optional[QgsFeatureRenderer]

virtual createSpatialIndex(self) → bool[source]¶

Creates a spatial index on the datasource (if supported by the provider type).

Return type:: bool
Returns:: True in case of success

virtual dataComment(self) → str[source]¶

Returns a short comment for the data that this provider is providing access to (e.g. the comment for postgres table).

Return type:: str

virtual defaultValue(self, fieldIndex: int) → Any[source]¶

Returns any literal default values which are present at the provider for a specified field index. Important - this should ONLY be called when creating an attribute to insert directly into the database. Do not call this method for non-feature creation or modification, e.g., when validating an attribute or to compare it against an existing value, as calling it can cause changes to the underlying data source (e.g., Postgres provider where the default value is calculated as a result of a sequence). It is recommended that you instead use the methods in QgsVectorLayerUtils such as QgsVectorLayerUtils.createFeature() so that default value handling and validation is automatically carried out.

See also

defaultValueClause()

Parameters:: fieldIndex (int)
Return type:: Any

virtual defaultValueClause(self, fieldIndex: int) → str[source]¶

Returns any default value clauses which are present at the provider for a specified field index. These clauses are usually SQL fragments which must be evaluated by the provider, e.g., sequence values.

See also

defaultValue()

Parameters:: fieldIndex (int)
Return type:: str

virtual deleteAttributes(self, attributes: Any) → bool[source]¶

Deletes existing attributes from the provider. If attributes are deleted using this method then QgsVectorLayer.updateFields() must be called manually to ensure that the layer’s field are correctly reported.

Parameters:: attributes (Any) – a set containing indices of attributes
Return type:: bool
Returns:: True in case of success and False in case of failure

virtual deleteFeatures(self, id: Any) → bool[source]¶

Deletes one or more features from the provider. This requires the DeleteFeatures capability.

Parameters:: id (Any) – list containing feature ids to delete
Return type:: bool
Returns:: True in case of success and False in case of failure

See also

truncate()

virtual dependencies(self) → Set[QgsMapLayerDependency]¶

Gets the list of layer ids on which this layer depends. This in particular determines the order of layer loading.

Return type:: Set[QgsMapLayerDependency]

virtual discoverRelations(self, target: QgsVectorLayer | None, layers: Iterable[QgsVectorLayer]) → List[QgsRelation]¶

Discover the available relations with the given layers.

Parameters:

target (Optional[QgsVectorLayer]) – the layer using this data provider.
layers (Iterable[QgsVectorLayer]) – the other layers.

Return type:

List[QgsRelation]

Returns:

the list of N-1 relations from this provider.

virtual doesStrictFeatureTypeCheck(self) → bool[source]¶

Returns True if the provider is strict about the type of inserted features (e.g. no multipolygon in a polygon layer)

Return type:: bool

virtual empty(self) → bool[source]¶

Returns True if the layer does not contain any feature.

Added in version 3.4.

Return type:: bool

encoding(self) → str[source]¶

Returns the encoding which is used for accessing data.

See also

setEncoding()

Return type:: str

virtual enumValues(self, index: int) → List[str][source]¶

Returns the possible enum values of an attribute. Returns an empty stringlist if a provider does not support enum types or if the given attribute is not an enum type.

Parameters:: index (int) – the index of the attribute
Return type:: List[str]
Returns:: reference to the list to fill

errors(self) → List[str][source]¶

Gets recorded errors

Return type:: List[str]

abstract featureCount(self) → int¶

Number of features in the layer

Return type:: int
Returns:: number of features

abstract featureSource(self) → QgsAbstractFeatureSource | None[source]¶

Returns feature source object that can be used for querying provider’s data. The returned feature source is independent from provider - any changes to provider’s state (e.g. change of subset string) will not be reflected in the feature source, therefore it can be safely used for processing in background without having to care about possible changes within provider that may happen concurrently. Also, even in the case of provider being deleted, any feature source obtained from the provider will be kept alive and working (they are independent and owned by the caller).

Sometimes there are cases when some data needs to be shared between vector data provider and its feature source. In such cases, the implementation must ensure that the data is not susceptible to run condition. For example, if it is possible that both feature source and provider may need reading/writing to some shared data at the same time, some synchronization mechanisms must be used (e.g. mutexes) to prevent data corruption.

Return type:: Optional[QgsAbstractFeatureSource]
Returns:: new instance of QgsAbstractFeatureSource (caller is responsible for deleting it)

fieldConstraints(self, fieldIndex: int) → QgsFieldConstraints.Constraints[source]¶

Returns any constraints which are present at the provider for a specified field index.

See also

skipConstraintCheck()

Parameters:: fieldIndex (int)
Return type:: QgsFieldConstraints.Constraints

fieldNameIndex(self, fieldName: str | None) → int[source]¶

Returns the index of a field name or -1 if the field does not exist

Parameters:: fieldName (Optional[str])
Return type:: int

fieldNameMap(self) → Any¶

Returns a map where the key is the name of the field and the value is its index

Return type:: Any

abstract fields(self) → QgsFields[source]¶

Returns the fields associated with this data provider.

Return type:: QgsFields

fillMinMaxCache(self)[source]¶: Populates the cache of minimum and maximum attribute values.

virtual forceReload(self)[source]¶: Deprecated since version 3.12.

Will be removed in QGIS 4.0 - use reloadData() instead.

virtual geometryColumnName(self) → str[source]¶

Returns the name of the column storing geometry, if applicable.

Added in version 3.42.

Return type:: str

abstract getFeatures(self, request: QgsFeatureRequest = QgsFeatureRequest()) → QgsFeatureIterator[source]¶

Query the provider for features specified in request.

Parameters:: request (QgsFeatureRequest = QgsFeatureRequest()) – feature request describing parameters of features to return
Return type:: QgsFeatureIterator
Returns:: iterator for matching features from provider

virtual handlePostCloneOperations(self, source: QgsVectorDataProvider | None)[source]¶

Handles any post-clone operations required after this vector data provider was cloned from the source provider.

Added in version 3.8.1.

Parameters:: source (Optional[QgsVectorDataProvider])

hasErrors(self) → bool[source]¶

Provider has errors to report

Return type:: bool

virtual hasFeatures(self) → Qgis.FeatureAvailability[source]¶

Will always return FeatureAvailability.FeaturesAvailable or FeatureAvailability.NoFeaturesAvailable.

Calls empty() internally. Providers should override empty() instead if they provide an optimized version of this call.

See also

empty()

Added in version 3.4.

Return type:: Qgis.FeatureAvailability

virtual hasMetadata(self) → bool[source]¶

Returns True if the data source has metadata, False otherwise.

Return type:: bool
Returns:: True if data source has metadata, False otherwise.

virtual isSqlQuery(self) → bool[source]¶

Returns True if the layer is a query (SQL) layer.

Note

this is simply a shortcut to check if the SqlQuery flag is set.

See also

vectorLayerTypeFlags()

Added in version 3.24.

Return type:: bool

virtual maximumValue(self, index: int) → Any[source]¶

Returns the maximum value of an attribute

Parameters:: index (int) – the index of the attribute

Default implementation walks all numeric attributes and caches minimal and maximal values. If provider has facilities to retrieve maximal value directly, override this function.

Return type:: Any

virtual metadata(self) → Dict[str, Any][source]¶

Gets metadata, dependent on the provider type, that will be display in the metadata tab of the layer properties.

Return type:: Dict[str, Any]
Returns:: The provider metadata

virtual minimumValue(self, index: int) → Any[source]¶

Returns the minimum value of an attribute

Parameters:: index (int) – the index of the attribute

Default implementation walks all numeric attributes and caches minimal and maximal values. If provider has facilities to retrieve minimal value directly, override this function.

Return type:: Any

nativeTypes(self) → List[QgsVectorDataProvider.NativeType]¶

Returns the names of the supported types

Return type:: List[QgsVectorDataProvider.NativeType]

palAttributeIndexNames(self) → Dict[int, str][source]¶

Returns list of indexes to names for QgsPalLabeling fix

Deprecated since version 3.32: This method is unused and will always return an empty hash.

Return type:: Dict[int, str]

virtual pkAttributeIndexes(self) → List[int][source]¶

Returns list of indexes of fields that make up the primary key

Return type:: List[int]

pushError(self, msg: str | None)[source]¶

Push a notification about errors that happened in this providers scope. Errors should be translated strings that require the users immediate attention.

For general debug information use QgsMessageLog.logMessage() instead.

Parameters:: msg (Optional[str])

signal raiseError[source]¶: Signals an error in this provider

virtual renameAttributes(self, renamedAttributes: Dict[int, str | None]) → bool[source]¶

Renames existing attributes. If attributes are renamed using this method then QgsVectorLayer.updateFields() must be called manually to ensure that the layer’s field are correctly reported.

Parameters:: renamedAttributes (Dict[int, Optional[str]]) – map of attribute index to new attribute name
Return type:: bool
Returns:: True in case of success and False in case of failure

virtual setEncoding(self, e: str | None)[source]¶

Set encoding used for accessing data from layer.

An empty encoding string indicates that the provider should automatically select the most appropriate encoding for the data source.

Warning

Support for setting the provider encoding depends on the underlying data provider. Check capabilities() for the QgsVectorDataProvider.SelectEncoding capability in order to determine if the provider supports this ability.

See also

encoding()

Parameters:: e (Optional[str])

setNativeTypes(self, nativeTypes: Iterable[QgsVectorDataProvider.NativeType])[source]¶

Set the list of native types supported by this provider. Usually done in the constructor.

Parameters:: nativeTypes (Iterable[QgsVectorDataProvider.NativeType])

virtual skipConstraintCheck(self, fieldIndex: int, constraint: QgsFieldConstraints.Constraint, value: Any = None) → bool[source]¶

Returns True if a constraint check should be skipped for a specified field (e.g., if the value returned by defaultValue() is trusted implicitly. An optional attribute value can be passed which can help refine the skip constraint check.

See also

fieldConstraints()

Parameters:

fieldIndex (int)
constraint (QgsFieldConstraints.Constraint)
value (Any = None)

Return type:

bool

virtual storageType(self) → str[source]¶

Returns the permanent storage type for this layer as a friendly name.

Return type:: str

supportedType(self, field: QgsField) → bool[source]¶

check if provider supports type of field

Parameters:: field (QgsField)
Return type:: bool

textEncoding(self) → QTextCodec | None[source]¶

Gets this providers encoding

Return type:: Optional[QTextCodec]

virtual transaction(self) → QgsTransaction | None[source]¶

Returns the transaction this data provider is included in, if any.

Return type:: Optional[QgsTransaction]

virtual translateMetadataKey(self, mdKey: str | None) → str[source]¶

Gets the translated metadata key.

Parameters:: mdKey (Optional[str]) – The metadata key
Return type:: str
Returns:: The translated metadata value

virtual translateMetadataValue(self, mdKey: str | None, value: Any) → str[source]¶

Gets the translated metadata value.

Parameters:

mdKey (Optional[str]) – The metadata key
value (Any) – The metadata value

Return type:

str

Returns:

The translated metadata value

virtual truncate(self) → bool[source]¶

Removes all features from the layer. This requires either the FastTruncate or DeleteFeatures capability. Providers with the FastTruncate capability will use an optimised method to truncate the layer.

Return type:: bool
Returns:: True in case of success and False in case of failure.

See also

deleteFeatures()

virtual uniqueStringsMatching(self, index: int, substring: str | None, limit: int = -1, feedback: QgsFeedback | None = None) → List[str][source]¶

Returns unique string values of an attribute which contain a specified subset string. Subset matching is done in a case-insensitive manner.

Parameters:

index (int) – the index of the attribute
substring (Optional[str]) – substring to match (case insensitive)
limit (int = -1) – maxmum number of the values to return, or -1 to return all unique values
feedback (Optional[QgsFeedback] = None) – optional feedback object for canceling request

Return type:

List[str]

Returns:

list of unique strings containing substring

virtual vectorLayerTypeFlags(self) → Qgis.VectorLayerTypeFlags[source]¶

Returns the vector layer type flags.

See also

isSqlQuery()

Added in version 3.24.

Return type:: Qgis.VectorLayerTypeFlags

abstract wkbType(self) → Qgis.WkbType[source]¶

Returns the geometry type which is returned by this layer

Return type:: Qgis.WkbType