An Introduction to Sql 11 (Code Name Denali) –Part VI (T-Sql Features in CTP 3)

using System;
using System.Collections.Generic;
using System.Data.SqlTypes;
using Microsoft.SqlServer.Server;

public partial class UserDefinedFunctions
{
    [Microsoft.SqlServer.Server.SqlFunction(DataAccess = DataAccessKind.Read)]

    public static SqlBoolean TryParseFn(string value, string dataType)
    {
        bool status = TryParse(value, dataType);
        return new SqlBoolean(status);
    }

    /// <summary>
    /// Function: TryParse
    /// Purpose: Converts a string value to the target type. If succeeds returns true else false
    /// </summary>
    /// <param name="val"></param>
    /// <param name="key"></param>
    /// <returns>bool</returns>
    private static bool TryParse(string val, string key)
    { 
        bool flag = true;

        Dictionary<string, System.Type> dict = new Dictionary<string, System.Type>();
        dict.Add("int", typeof(Int32));
        dict.Add("bigint", typeof(Int64));
        dict.Add("datetime", typeof(DateTime));
        dict.Add("numeric", typeof(Decimal));

        try
        {
            switch (dict[key].FullName)
            {
                case "System.Int32":Int32.Parse(val);break; 
                case "System.Int64":Int64.Parse(val); break; 
                case "System.DateTime":DateTime.Parse(val); break;
                case "System.Decimal": Decimal.Parse(val); break;
            }
        }
        catch
        {
            flag = !flag;
        }
        return flag;        
    }
}