MySQL:在某些条件下更新表

时间:2018-05-02 17:39:35

标签: mysql sql-update sql-insert

我有2个表,主表和当前表(刷新非常小时)。 这两个表都有相同的结构:

Chk |描述|州|日期

我需要在主表中更新/追加(添加新行),如果:

1)具有新ID或

的行

2)如果特定变量(在这种情况下,状态')已经改变。我尝试使用以下方法做到这一点没有成功:

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))

有关如何实现这一目标的任何指示?

2 个答案:

答案 0 :(得分:1)

我尝试在两个单独的步骤中执行此操作:

1)首先,我将所有新行附加ID:这有效

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));

然而,我试图在下面做错误

2)然后更换“状态”'具有新值的变量:

 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。

这是什么意思?

答案 1 :(得分:1)

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;

<强>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     |
+------+----------------+-----------------+----------------+