SQLite:使用另一个表中的值更新列

Question

我有2个sqlite表:

table1(id INTEGER AUTOINCREMENT,状态TEXT,名称TEXT);

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

table2(状态TEXT,名称TEXT,trans_id INTEGER);

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

我想更新从table2到table1的状态和名称,其中table1.id = table2.trans_id

我有这个问题:

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table1.这是结果table1

| 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？我怎样才能实现它？

Answer 1

我假设t2.trans_id是uniq或primary key在table2.如果没有,那么如果它返回多个结果,则更新查询将爆炸.在这种情况下,您需要使用更多过滤器,WHERE 或者TOP 1如果需要任何结果则使用.

           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)

Answer 2

如果 table2 中有 id 列，则之前的答案将失败。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);