DbExpressionBuilder.ThenByDescending Method

 

Creates a new DbSortExpression that with a sort order that includes the sort order of the given order input set together with the specified sort key in descending sort order and with default collation.

Namespace:   System.Data.Entity.Core.Common.CommandTrees.ExpressionBuilder
Assembly:  EntityFramework (in EntityFramework.dll)

NameDescription
System_CAPS_pubmethodSystem_CAPS_staticThenByDescending(DbSortExpression, Func<DbExpression, DbExpression>)

Creates a new DbSortExpression that with a sort order that includes the sort order of the given order input set together with the specified sort key in descending sort order and with default collation.

System_CAPS_pubmethodSystem_CAPS_staticThenByDescending(DbSortExpression, Func<DbExpression, DbExpression>, String)

Creates a new DbSortExpression that with a sort order that includes the sort order of the given order input set together with the specified sort key in descending sort order and with the specified collation.


DbExpressionBuilder.ThenByDescending Method (DbSortExpression, Func<DbExpression, DbExpression>)

Creates a new DbSortExpression that with a sort order that includes the sort order of the given order input set together with the specified sort key in descending sort order and with default collation.

public static DbSortExpression ThenByDescending(
	this DbSortExpression source,
	Func<DbExpression, DbExpression> sortKey
)

Parameters

source
Type: System.Data.Entity.Core.Common.CommandTrees.DbSortExpression

A DbSortExpression that specifies the ordered input set.

sortKey
Type: System.Func<DbExpression, DbExpression>

A method that specifies how to derive the additional sort key expression given a member of the input set. This method must produce an expression with an order-comparable result type that provides the sort key definition.

Return Value

Type: System.Data.Entity.Core.Common.CommandTrees.DbSortExpression

A new DbSortExpression that represents the new overall order-by operation.

Exception Condition
ArgumentNullException

source or sortKey is null.

ArgumentNullException

The expression produced by sortKey is null.

ArgumentException

source does not have a collection result type.

ArgumentException

The expression produced by sortKey does not have an order-comparable result type.


DbExpressionBuilder.ThenByDescending Method (DbSortExpression, Func<DbExpression, DbExpression>, String)

Creates a new DbSortExpression that with a sort order that includes the sort order of the given order input set together with the specified sort key in descending sort order and with the specified collation.

public static DbSortExpression ThenByDescending(
	this DbSortExpression source,
	Func<DbExpression, DbExpression> sortKey,
	string collation
)

Parameters

source
Type: System.Data.Entity.Core.Common.CommandTrees.DbSortExpression

A DbSortExpression that specifies the ordered input set.

sortKey
Type: System.Func<DbExpression, DbExpression>

A method that specifies how to derive the additional sort key expression given a member of the input set. This method must produce an expression with an order-comparable result type that provides the sort key definition.

collation
Type: System.String

The collation to sort under.

Return Value

Type: System.Data.Entity.Core.Common.CommandTrees.DbSortExpression

A new DbSortExpression that represents the new overall order-by operation.

Exception Condition
ArgumentNullException

source, sortKey or collation is null.

ArgumentNullException

The expression produced by sortKey is null.

ArgumentException

source does not have a collection result type.

ArgumentException

The expression produced by sortKey does not have an order-comparable string result type.

ArgumentOutOfRangeException

collation is empty or contains only space characters.