Linq To SQL Update Delete

  public static class StaticClass
    {
        ///<summary>
        /// 批量删除
        ///</summary>
        ///<typeparam name="T"></typeparam>
        ///<param name="table"></param>
        ///<param name="predicate"></param>
        ///<returns></returns>
        public static int Delete<T>(this Table<T> table, Expression<Func<T, bool>> predicate) where T : class
        {
            string tableName = table.Context.Mapping.GetTable(typeof(T)).TableName;
            DbCommand command=table.Context.GetCommand(table.Where(predicate));
            string sqlCondition = command.CommandText;
            sqlCondition = sqlCondition.Substring(sqlCondition.LastIndexOf("WHERE ", StringComparison.InvariantCultureIgnoreCase) + 6);
            // 去掉表中出现的 t0
            sqlCondition = sqlCondition.Replace("[t0].", "");
            string commandText = string.Format("Delete  FROM {0}  WHERE {1}", tableName , sqlCondition);
            command.CommandText = commandText;
   

            //执行 
            try
            {
                if (command.Connection.State != ConnectionState.Open)
                {
                    command.Connection.Open();
                }
                return command.ExecuteNonQuery();
            }
            finally
            {
                command.Connection.Close();
                command.Dispose();
            }

        }

        ///<summary>
        /// 批量更新
        ///</summary>
        ///<typeparam name="T"></typeparam>
        ///<param name="table"></param>
        ///<param name="predicate">查询条件表达式</param>
        ///<param name="updater">更新表达式</param>
        ///<returns>影响的行数</returns>
        public static int Update<T>(this Table<T> table, Expression<Func<T, bool>> predicate, Expression<Func<T, T>> updateExp) where T : class
        {
            string tableName = table.Context.Mapping.GetTable(typeof(T)).TableName;
            DbCommand command = table.Context.GetCommand(table.Where(predicate));
            string sqlCondition = command.CommandText;
            sqlCondition = sqlCondition.Substring(sqlCondition.LastIndexOf("WHERE ", StringComparison.InvariantCultureIgnoreCase) + 6);

            //获取Update的赋值语句
            var updateMemberExp = (MemberInitExpression)updateExp.Body;
            var updateMemberCollection = updateMemberExp.Bindings.Cast<MemberAssignment>().Select(c =>
            {
                var p = command.CreateParameter();
                p.ParameterName = c.Member.Name;
                p.Value = ((ConstantExpression)c.Expression).Value;
                return p;
            }).ToArray();

            string sqlUpdateBlock = string.Join(", ", updateMemberCollection.Select(c => string.Format("[{0}]=@{0}", c.ParameterName)).ToArray());

            //组合SQL 语句
            string commandText = string.Format("UPDATE {0} SET {1} FROM {0} AS t0 WHERE {2}", tableName, sqlUpdateBlock, sqlCondition);

            //获取参数数组 
            command.Parameters.AddRange(updateMemberCollection);
            command.CommandText = commandText;
            //执行 
            try
            {
                if (command.Connection.State != ConnectionState.Open)
                {
                    command.Connection.Open();
                }
                return command.ExecuteNonQuery();
            }
            finally
            {
                command.Connection.Close();
                command.Dispose();
            }
        }
    }

// 查询
          DataClasses1DataContext dbo = new DataClasses1DataContext();
            Table<K_Menu> tb = dbo.GetTable<K_Menu>();
            List<K_MenuCopy> list;//= new List<K_Menu>();
            using (DbConnection dbCon = tb.Context.Connection)
            {
                var query1 = tb.Select(a => new { a.BigImage, a.Image, a.MenuID });
                DbCommand dbCommand = tb.Context.GetCommand(query1);
                dbCon.Open();
                using (DbDataReader dr = dbCommand.ExecuteReader(CommandBehavior.CloseConnection))
                {
                    list = dbo.Translate<K_MenuCopy>(dr).ToList();
                }

            }