使用SQLite从另一个表中更新列的值?

cgvd09ve  于 2023-05-23  发布在  SQLite
关注(0)|答案(2)|浏览(172)

我有两个SQLite表。我想用table2中的值更新table1中的列。
表1,table1 (id INTEGER AUTOINCREMENT, status TEXT, name TEXT);

| id |  status   | name |
|----|-----------|------|
|  1 | pending   | xyz  |
|  2 | completed | abc  |

表2,table2 (status TEXT, name TEXT, trans_id INTEGER);

| trans_id |  status   | name |
|----------|-----------|------|
|        1 | refunded  | cvb  |
|        2 | cancelled | asd  |

我想将状态和名称从表2更新到表1,其中table1.id = table2.trans_id。我有这个疑问:

UPDATE table1 
SET status = (SELECT t2.status FROM table1 t1,table2 t2 WHERE t1.id = t2.trans_id) , 
name = (SELECT t2.name FROM table1 t1,table2 t2 WHERE t1.id = t2.trans_id)
WHERE id IN (SELECT trans_id FROM table1 t1,table2 t2 WHERE t1.id = t2.trans_id)

它错误地填充了表1。这是生成的表1

| id |  status  | name |
|----|----------|------|
|  1 | refunded | cvb  |
|  2 | refunded | cvb  |

我的要求是:

| id |  status   | name |
|----|-----------|------|
|  1 | refunded  | cvb  |
|  2 | cancelled | asd  |

我的查询有什么问题?我怎么才能做到呢?

vxqlmq5t

vxqlmq5t1#

我假设t2.trans_iduniqtable2中的primary key。如果不是,那么如果它返回多个结果,那么更新查询将爆炸。在这种情况下,您需要使用WHERETOP 1应用更多过滤器,如果需要任何结果。

UPDATE table1
SET    status = (SELECT t2.status
                 FROM   table2 t2
                 WHERE  t2.trans_id = id),
       NAME = (SELECT t2.NAME
               FROM   table2 t2
               WHERE  t2.trans_id = id)
WHERE  id IN (SELECT trans_id
              FROM   table2 t2
              WHERE  t2.trans_id = id)
9lowa7mx

9lowa7mx2#

如果table2中存在id列,则前面的回答将失败。最好使用全名table1.id

UPDATE table1 
SET status = (SELECT t2.status FROM table2 t2 WHERE t2.trans_id = table1.id) , 
    name = (SELECT t2.name FROM table2 t2 WHERE t2.trans_id = table1.id)
WHERE id IN (SELECT trans_id FROM table2 t2 WHERE t2.trans_id= table1.id);

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