using System;

public class Program

{

    public static void Main()

    {   

        RunExpectedFailureTest(null);

        RunExpectedFailureTest("");

        RunExpectedFailureTest("   \t");

        RunTest("blah");

        RunTest("/tell/me/something/good");

        RunTest("/nfl/*");      

        RunTest("/nba/teams/*");        

    }

    public static void RunTest(string tag) {

        var result = TransformTag(tag);     

        Console.WriteLine($"{tag} transformed to {result.TransformedStringForSqlSearch} and needs wildcard search: {result.NeedsWildcardSearch}");      

    }

    public static void RunExpectedFailureTest(string tag) {

        try {

            RunTest(tag);

            throw new Exception("Expected RunTest to throw an error");

        } catch (ArgumentOutOfRangeException) {

            Console.WriteLine("Expected ArgumentOutOfRangeException");

        }

    }

    public static TagTransformResult TransformTag(string tag) {

        if (String.IsNullOrWhiteSpace(tag)) throw new ArgumentOutOfRangeException(nameof(tag));

        const string Wildcard = "*";

        const string SqlServerEquivalentOfWildcard = "%";

        return new TagTransformResult {

                NeedsWildcardSearch = (tag ?? String.Empty).Contains(Wildcard),

                TransformedStringForSqlSearch = (tag ?? String.Empty).Replace(Wildcard, SqlServerEquivalentOfWildcard)

        };          

    }

}

​

​

​

public class TagTransformResult

{

    public bool NeedsWildcardSearch { get; set; }   

    public string TransformedStringForSqlSearch {get;set;}

}