public static DbValue FORMAT(DbFunctionTools tools, DbFunctionArguments args)
        {
            string FunctionName = "FORMAT";

            args.EnsureCount(FunctionName, 2);

            DbType    arg0type;
            ByteSlice arg0 = args[0].Eval(out arg0type);
            DbType    arg1type;
            ByteSlice arg1 = args[1].Eval(out arg1type);

            if (Types.IsNullValue(arg0))
            {
                return(tools.AllocNullValue()); // Give a null, take a null.
            }
            if (arg0type.ID != DbTypeID.CHARS)
            {
                args.Expected(FunctionName, 0, "input CHAR(n), got " + arg0type.Name.ToUpper());
            }
            if (Types.IsNullValue(arg1))
            {
                return(tools.AllocNullValue()); // Give a null, take a null.
            }
            if (arg1type.ID != DbTypeID.DATETIME)
            {
                args.Expected(FunctionName, 0, "input DATETIME, got " + arg1type.Name.ToUpper());
            }

            string   formatstr = tools.GetString(arg0).ToString();
            DateTime dt        = tools.GetDateTime(arg1);

            mstring result = mstring.Prepare(dt.ToString(formatstr));

            while (result.Length < 80)
            {
                result.MAppend('\0');
            }
            return(tools.AllocValue(result));
        }