用MySQL将列合并成行？

2024-05-13 13:58:06 380

语法

select yourColumnName1 from yourTableName union all select yourColumnName2 from yourTableName;

让我们首先创建一个表-

mysql> create table DemoTable -> ( -> Value1 int, -> Value2 int -> );

使用插入命令在表中插入一些记录-

mysql> insert into DemoTable values(100,200); mysql> insert into DemoTable values(500,600);

使用select语句显示表中的所有记录-

mysql> select *from DemoTable;

这将产生以下输出-

+--------+--------+ | Value1 | Value2 | +--------+--------+ | 100 | 200 | | 500 | 600 | +--------+--------+ 2 rows in set (0.00 sec)

这是将列合并为行的查询-

mysql> select Value1 from DemoTable -> union all -> select Value2 from DemoTable;

这将产生以下输出-

+--------+ | Value1 | +--------+ | 100 | | 500 | | 200 | | 600 | +--------+ 4 rows in set (0.00 sec)

语法