Sorry, i just noticed i have replaced your code with mine. This function is also valid, but for single Character only.

Following is the complete code

using System;

using System.Data;

using Microsoft.SqlServer.Dts.Pipeline.Wrapper;

using Microsoft.SqlServer.Dts.Runtime.Wrapper;

using System.Text.RegularExpressions;

[Microsoft.SqlServer.Dts.Pipeline.SSISScriptComponentEntryPointAttribute]

public class ScriptMain : UserComponent

{

public override void PreExecute()

{

base.PreExecute();

}

public override void PostExecute()

{

base.PostExecute();`enter code here`

}

public override void Input0_ProcessInputRow(Input0Buffer Row)

{

if (Regex.IsMatch(Row.ID, "^(0|[1-9][0-9]*)$"))

{

Row.isvalid = true;

}

else

{

Row.isvalid = false;

}

}

I have updated the regular expression. hope it helps