mysql-MySql参数化查询结果为空

 private const string SQL_GetPermissionInfo = @"                  SELECT                         PermissionID                        ,PermissionName                        ,CreateDate                        ,CreateUserID                        ,UpdateDate                        ,UpdateUserID                        ,ValidFlag                    FROM                        Permission                   WHERE                        1=1 ";    public static DBResponse GetPermissionInfo(DBRequest dbRequest, string PermissionID)        {            StringBuilder sqlStr = new StringBuilder();            sqlStr.Append(SQL_GetPermissionInfo);            MySqlParameter[] paras = null;            if (!string.IsNullOrEmpty(PermissionID))            {                paras = new MySqlParameter[]{                    new MySqlParameter("@PermissionID ",PermissionID )                };                sqlStr.Append(" and PermissionID  = @PermissionID ");            }            return ExecuteDataset(dbRequest, sqlStr.ToString(), paras);        }