mysql - SQL 查询将字段值复制到同一个表中

Question

我有一个表(post_order)，结构如下:

   | post_id | term_id | post_type | taxonomy |
   |    1    |    6    |    post   | category |
   |    2    |    6    |    post   | category |
   |    3    |    6    |    post   | category |

我想将所有字段复制到同一个表中，但更改 term_id(例如 7)，因此表最终将如下所示:

   | post_id | term_id | post_type | taxonomy |
   |    1    |    6    |    post   | category |
   |    2    |    6    |    post   | category |
   |    3    |    6    |    post   | category |
   |    1    |    7    |    post   | category |
   |    2    |    7    |    post   | category |
   |    3    |    7    |    post   | category |

我知道我可以做这样的事情:

INSERT INTO post_order (post_id, term_id, post_type, taxonomy)
SELECT post_id, term_id, post_type, taxonomy
FROM post_order
WHERE term_id = 6

但这会产生完全相同的重复，并且不会更改 term_id。

我怎样才能做到这一点？

Answer 1

在 INSERT 语句中将 term_id 硬编码为 7:

INSERT INTO post_order (post_id, term_id, post_type, taxonomy)
SELECT post_id, 7, post_type, taxonomy
FROM post_order
WHERE term_id = 6