示例代码如下
SELECT
*
FROM
(
SELECT 1 AS t_type, title, inputtime FROM table1
UNION
SELECT 2 AS t_type, title, inputtime FROM table2
) AS a
ORDER BY
inputtime DESC
LIMIT 0, 4;
查完后会多出一列t_type表示数据来自哪个表
在数据量较小的情况下测试过; 没有在大数据量下进行测试.