DataAccessAdapterCoreGetDbCount Method (IEntityCollection2, IRelationPredicateBucket, IGroupByCollection) |
Gets the estimated number of objects returned by a query for objects to store in the entity collection passed in, using the filter and
groupby clause specified. The number is estimated as duplicate objects can be present in the plain query results, but will be filtered out
when the query result is transformed into objects.
Namespace:
SD.LLBLGen.Pro.ORMSupportClasses
Assembly:
SD.LLBLGen.Pro.ORMSupportClasses (in SD.LLBLGen.Pro.ORMSupportClasses.dll) Version: 5.4.0.0 (5.4.0)
Syntax public int GetDbCount(
IEntityCollection2 collection,
IRelationPredicateBucket filter,
IGroupByCollection groupByClause
)
Public Function GetDbCount (
collection As IEntityCollection2,
filter As IRelationPredicateBucket,
groupByClause As IGroupByCollection
) As Integer
Parameters
- collection
- Type: SD.LLBLGen.Pro.ORMSupportClassesIEntityCollection2
EntityCollection instance which will be fetched by the query to get the rowcount for - filter
- Type: SD.LLBLGen.Pro.ORMSupportClassesIRelationPredicateBucket
filter to use by the query to get the rowcount for - groupByClause
- Type: SD.LLBLGen.Pro.ORMSupportClassesIGroupByCollection
The list of fields to group by on. When not specified or an empty collection is specified, no group by clause
is added to the query. A check is performed for each field in the selectList. If a field in the selectList is not present in the groupByClause
collection, an exception is thrown.
Return Value
Type:
Int32the number of rows the query for the fields specified, using the filter, relations and groupbyClause specified.
Implements
IDataAccessAdapterGetDbCount(IEntityCollection2, IRelationPredicateBucket, IGroupByCollection)Remarks This method performs a SELECT COUNT(*) FROM (actual query) and executes that as a scalar query. This construct is not supported on
Firebird. You can try to achieve the same results by using GetScalar and AggregateFunction.CountRow, though those results can differ from
the result returned by GetDbCount if you use a group by clause.
See Also