Question

我的nav_item表格如下：

+----+--------+--------+--------+------+-----+
| id | nav_id | active | name   | link | ... |
+----+--------+--------+--------+------+-----+
| 1  |    1   |    1   | Item 1 | .......... |
| 2  |    2   |    1   | Item 2 | .......... |
| 3  |    1   |    1   | Item 3 | .......... |
| 4  |    3   |    1   | Item 4 | .......... |
| 5  |    1   |    1   | Item 5 | .......... |
+----+--------+--------+--------+------+-----+

我的目标是复制所有nav_id = 1的记录。所以这个命令将起到魔力：insert into nav_item select * from nav_item where nav_id=1;

但我不希望所有人都nav_id相同。因此，所有新克隆都应该nav_id，例如4。但是，如何复制所有这些内容并使用单个命令将nav_id更改为我想要的任何内容？

Answer 1

您可以使用以下查询：

INSERT INTO nav_item
    SELECT      NULL,
                4,
                active,
                name,
                link,
                ...
        FROM    nav_item
        WHERE   nav_id = 1;

Answer 2

试试这个;）

insert into nav_item
select (t.id, t.nav_id, t.active, t.name, t.link, ...)
from (
    select nav_item.id, @nav_id := @nav_id + 1 as nav_id, nav_item.active, nav_item.name, nav_item.link, ...information_schema.
    from nav_item join (select @nav_id := (select max(nav_id) from nav_item) tmp) where nav_item.nav_id = 1
) t

通过条件在DB中重复记录并更改单个值

2 个答案: