mysql 使用 JOIN 将 2 个表插入到另一个表中

Question

我有 2 个表:

表 1:

+-----+-----+-------+
| ID  | num | title |
+-----+-----+-------+
| 101 |  0  | pro   |
+-----+-----+-------+
| 102 |  0  | xtr   |
+-----+-----+-------+
| 103 |  0  | low   |
+-----+-----+-------+
| 104 |  0  | hi    |
+-----+-----+-------+

和表2:

+-----+--------+
| Nn  | title  |
+-----+--------+
|  1  | ttl1   |
+-----+--------+
|  2  | ttl2   |
+-----+--------+
|  3  | ttl3   |
+-----+--------+

我需要 mysql 请求来填充表 3，例如:

+-----+-----+
| ID  | Nn  |
+-----+-----+
| 101 |  1  |
+-----+-----+
| 101 |  2  |
+-----+-----+
| 101 |  3  |
+-----+-----+
| 102 |  1  |
+-----+-----+
| 102 |  2  |
+-----+-----+
| 102 |  3  |
+-----+-----+
| 103 |  1  |
+-----+-----+
| 103 |  2  |
+-----+-----+
| 103 |  3  |
...

即对于 table1 中的每个 ID，我需要 table2 中的所有 Nn。

我写了下面的sql请求，效果很好，但是我需要sql请求才能使用JOIN语句，我该怎么做呢？

INSERT INTO `table3` ( `ID`, `Nn` ) 
     SELECT `t1`.`ID`, `t2`.`Nn` 
     FROM `table1` as `t1`, `table2` as `t2`;

Answer 1

使用 cross join :

INSERT INTO `table3` ( `ID`, `Nn` ) 
 SELECT `t1`.`ID`, `t2`.`Nn` 
 FROM `table1` as `t1` CROSS JOIN `table2` as `t2`;