Escaping the escape character does not work – SQL LIKE Operator

Question

I have used \\ as escape character for LIKE operator. I am escaping following four characters

1 % 2 [

Answer 1

C# Code for LIKE handling

     public static string WildcardFormatSpecialCharacter(string source)
    {
        string formattedResult = string.Empty;
        if (!String.IsNullOrEmpty(source))
        {
            //Escape the escape character
            formattedResult = source.Replace(DataLayerConstants.EscapeCharacter, DataLayerConstants.EscapeCharacterWithEscape);
            //The %
            formattedResult = formattedResult.Replace(DataLayerConstants.Percentage, DataLayerConstants.PercentageWithEscape);
            //The [
            formattedResult = formattedResult.Replace(DataLayerConstants.OpenSqaureBracket, DataLayerConstants.OpenSqaureBracketWithEscape);
            //The ]
            formattedResult = formattedResult.Replace(DataLayerConstants.CloseSqaureBracket, DataLayerConstants.CloseSqaureBracketWithEscape);
            //The _
            formattedResult = formattedResult.Replace(DataLayerConstants.Underscore, DataLayerConstants.UnderscoreWithEscape);
        }
        return formattedResult;
    }


    public const string EscapeCharacter = @"\";
    public const string EscapeCharacterWithEscape = @"\\";
    public const string Percentage = "%";
    public const string PercentageWithEscape = @"\%";
    public const string OpenSqaureBracket = "[";
    public const string OpenSqaureBracketWithEscape = @"\[";
    public const string CloseSqaureBracket = "]";
    public const string CloseSqaureBracketWithEscape = @"\]";
    public const string Underscore = "_";
    public const string UnderscoreWithEscape = @"\_";

Other things to check Use of REPLACE in SQL Query for newline/ carriage return characters

Answer 2

Modify your CustomFormat method like this:

private static string CustomFormat(string input)
{
    input = input.Replace(@"\", @"\\"); 
    input = input.Replace(@"%", @"\%");
    input = input.Replace(@"[", @"\[");
    input = input.Replace(@"]", @"\]");
    input = input.Replace(@"_", @"\_");
    return input;
}