EdmFunctions.Substring Method (DbExpression, DbExpression, DbExpression)
Creates a DbFunctionExpression that invokes the canonical 'Substring' function with the specified arguments, which must have a string and integer numeric result types. The result type of the expression is string.
Assembly: EntityFramework (in EntityFramework.dll)
public static DbFunctionExpression Substring( this DbExpression stringArgument, DbExpression start, DbExpression length )
Parameters
- stringArgument
-
Type:
System.Data.Entity.Core.Common.CommandTrees.DbExpression
An expression that specifies the string from which to extract the substring.
- start
-
Type:
System.Data.Entity.Core.Common.CommandTrees.DbExpression
An expression that specifies the starting index from which the substring should be taken.
- length
-
Type:
System.Data.Entity.Core.Common.CommandTrees.DbExpression
An expression that specifies the length of the substring.
Return Value
Type: System.Data.Entity.Core.Common.CommandTrees.DbFunctionExpressionA new DbFunctionExpression that returns the substring of length length from stringArgument starting at start.
Exception | Condition |
---|---|
ArgumentNullException | stringArgument, start or length is null. |
ArgumentException | No overload of the canonical 'Substring' function accepts arguments with the result types of stringArgument, start and length. |
Substring requires that the index specified by start be <b>1-based</b>.