45.笔记 MySQL学习——FROM子句里的子查询
子查询可以用在FROM子句里，已生成某些值。
例如：
mysql> select * from (select 1,2 ) as t1 innerjoin (select 3,4) as t2;
+---+---+---+---+
| 1 | 2 | 3 | 4 |
+---+---+---+---+
| 1 | 2 | 3 | 4 |
+---+---+---+---+
1 row in set (0.01 sec)
45.笔记 MySQL学习——FROM子句里的子查询
子查询可以用在FROM子句里，已生成某些值。
例如：
mysql> select * from (select 1,2 ) as t1 innerjoin (select 3,4) as t2;
+---+---+---+---+
| 1 | 2 | 3 | 4 |
+---+---+---+---+
| 1 | 2 | 3 | 4 |
+---+---+---+---+
1 row in set (0.01 sec)