AsyncSelfServicingExtensionMethods.GetScalarAsync(TValue) Method (IDao, DynamicQuery, ITransaction, CancellationToken)

AsyncSelfServicingExtensionMethodsGetScalarAsyncTValue Method (IDao, DynamicQuery, ITransaction, CancellationToken)

Async variant of GetScalarTValue(IDao, DynamicQuery, ITransaction). Fetches a scalar value using the query specified, and returns this value typed as TValue, using a cast. The query specified will be converted to a scalar query prior to execution.

Namespace: SD.LLBLGen.Pro.QuerySpec.SelfServicing
Assembly: SD.LLBLGen.Pro.ORMSupportClasses (in SD.LLBLGen.Pro.ORMSupportClasses.dll) Version: 5.0.0.0 (5.0.0)

Syntax

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public static Task<TValue> GetScalarAsync<TValue>(
	this IDao dao,
	DynamicQuery query,
	ITransaction transactionToUse,
	CancellationToken cancellationToken
)

<ExtensionAttribute>
Public Shared Function GetScalarAsync(Of TValue) ( 
	dao As IDao,
	query As DynamicQuery,
	transactionToUse As ITransaction,
	cancellationToken As CancellationToken
) As Task(Of TValue)

Parameters

dao: Type: SD.LLBLGen.Pro.ORMSupportClassesIDao
The DAO instance.
query: Type: SD.LLBLGen.Pro.QuerySpecDynamicQuery
The query.
transactionToUse: Type: SD.LLBLGen.Pro.ORMSupportClassesITransaction
The transaction to use.
cancellationToken: Type: System.ThreadingCancellationToken
The cancellation token.

Type Parameters

TValue: The type of the value to return.

Return Value

Type: TaskTValue
the value to fetch

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IDao. When you use instance method syntax to call this method, omit the first parameter. For more information, see Extension Methods (Visual Basic) or Extension Methods (C# Programming Guide).

Remarks

Use nullable(Of T) for scalars which are a value type, to avoid crashes when the scalar query returns a NULL value.

Reference

AsyncSelfServicingExtensionMethods Class

GetScalarAsync Overload

SD.LLBLGen.Pro.QuerySpec.SelfServicing Namespace