Function to Trim any Character/String from Left of varchar in SQL Server

An Extended Left Trim (LTRIM) Function for SQL Server which removes given string/character from Left of another varchar (String)

Level: Intermediate

Knowledge Required:

• T-SQL
• SQL Server 2005
• SQL Server User Define Functions

Description:
The SQL Server's built-in LTrim() function removes only the blanks (spaces) from Left of a varchar (string). Here is a User Defined function which can remove any character.

CREATE FUNCTION [dbo].[LTrimString]
(
 -- Add the parameters for the function here
 @StringToTrim varchar(max),
 @CharToTrim varchar(10)
)
RETURNS varchar(max)
AS
BEGIN
    -- Declare the return variable here
    DECLARE @Result varchar(max);
    DECLARE @i int;
    DECLARE @l int;
    DECLARE @sl int;

    SET @i = 1;
    SET @l = Len(@StringToTrim);
    SET @sl = Len(@CharToTrim);
    While @i < @l
    Begin  
            If SubString(@StringToTrim, @i, @sl) <> @CharToTrim
            Begin
                SET @Result = SubString(@StringToTrim, @i, @l - @i + 1);
                Break;
            End
        SET @i = @i + @sl;
    End

    SET @Result = IsNull(@Result, @StringToTrim);

    -- Return the result of the function
    RETURN @Result;
END

Usage:

Print dbo.LTrimString('00000005221', '0')

Output:

5221