mysql：在一定条件下更新表

oyxsuwqo 于 2021-06-21 发布在 Mysql

关注(0)|答案(2)|浏览(437)

我有两个表，主表和当前表（每小时刷新一次）。两张table的结构相同：
chk |描述|状态|日期
如果出现以下情况，我需要更新/追加（添加新行）到主表中：
1）具有新ID的行或
2）如果某个特定变量（本例中为“state”）已更改。我试着用下面的方法来做，但没有成功：

INSERT  into AGILE_TICKETS_DLY 
SELECT * FROM CURR_AGILE_TICKETS curr
  WHERE EXISTS (SELECT * FROM AGILE_TICKETS_DLY mstr
          WHERE (curr.chk != mstr.chk) OR ( curr.chk = mstr.chk and 
    mstr.state != curr.state))

关于如何做到这一点有什么建议吗？

mysql sql-update sql-insert

来源：https://stackoverflow.com/questions/50140556/mysql-update-table-upon-certain-conditions

2条答案

按热度按时间

34gzjxbg1#

我试着分两步来做：
1）首先，我用id追加所有新行：这很有效

INSERT  into AGILE_TICKETS_DLY 
 SELECT * FROM CURR_AGILE_TICKETS curr
  WHERE not EXISTS (SELECT * FROM AGILE_TICKETS_DLY mstr
          WHERE (curr.chk = mstr.chk));

但后来，我试着在下面做了一个错误
2）然后用新值替换“state”变量：

INSERT  into AGILE_TICKETS_DLY_1 (state)
SELECT state 
  from CURR_AGILE_TICKETS_1 curr
where exists ( select * from AGILE_TICKETS_DLY_1 mstr where curr.chk = 
       mstr.chk);

但这给了我一个错误：
sql错误（1364）：字段“chk”没有默认值。
那是什么意思？

赞(0）回复(0）举报 2021-06-21

mitkmikd2#

您可以尝试这对查询：

-- insert new rows
insert into agile_tickets_dly
select * from curr_agile_tickets 
where chk not in (select chk from agile_tickets_dly);

-- update updated rows
update agile_tickets_dly x
join 
(
    select b.chk chk,b.description description,b.state state,b.date date 
    from agile_tickets_dly a, curr_agile_tickets b
    where 
        a.chk=b.chk and
        (a.description != b.description or a.state != b.state or a.date != b.date)
) y
on x.chk=y.chk
set x.description = y.description, x.state= y.state, x.date = y.date;

插图：

select * from agile_tickets_dly;
+------+-------------+---------+------------+
| chk  | description | state   | date       |
+------+-------------+---------+------------+
| 0    | desc-0      | state-1 | 01-01-2017 |
| 1    | desc-1      | state-1 | 01-01-2018 |
| 2    | desc-2      | state-2 | 01-02-2018 |
| 3    | desc-3      | state-3 | 01-03-2018 |
+------+-------------+---------+------------+

-- one new row with chk=4, three updated rows with chk=1,2,3
select * from curr_agile_tickets;
+------+----------------+-----------------+----------------+
| chk  | description    | state           | date           |
+------+----------------+-----------------+----------------+
| 0    | desc-0         | state-1         | 01-01-2017     |
| 1    | desc-1         | state-1         | date-1-updated |
| 2    | desc-2-updated | state-2         | 01-02-2018     |
| 3    | desc-3         | state-3-updated | 01-03-2018     |
| 4    | desc-4         | state-4         | 01-04-2018     |
+------+----------------+-----------------+----------------+

-- after executing the two queries
select * from agile_tickets_dly;
+------+----------------+-----------------+----------------+
| chk  | description    | state           | date           |
+------+----------------+-----------------+----------------+
| 0    | desc-0         | state-1         | 01-01-2017     |
| 1    | desc-1         | state-1         | date-1-updated |
| 2    | desc-2-updated | state-2         | 01-02-2018     |
| 3    | desc-3         | state-3-updated | 01-03-2018     |
| 4    | desc-4         | state-4         | 01-04-2018     |
+------+----------------+-----------------+----------------+

赞(0）回复(0）举报 2021-06-21

我来回答

mysql：在一定条件下更新表

2条答案

相关问题

热门标签

最新问答