Question

只要tbl1中存在多于1条记录且tbl1_temp中没有

，该查询就会出错

如何解决此问题，以便对于tbl1_temp中不存在的每条记录，更新tbl1中相应记录的状态

UPDATE tbl1 SET Status = 'Finished' 
WHERE id = (SELECT id 
FROM tbl1 
WHERE NOT EXISTS (SELECT id FROM tbl1_temp 
WHERE tbl1.id = tbl1_temp.id))

Answer 1

UPDATE tbl1
SET Status = 'Finished' 
WHERE NOT EXISTS (SELECT id FROM tbl1_temp 
    WHERE tbl1.id = tbl1_temp.id)

Answer 2

直接使用NOT EXISTS

UPDATE tbl1
SET Status = 'Finished' 
WHERE NOT EXISTS (SELECT * FROM tbl1_temp
                WHERE tbl1.id = tbl1_temp.id)

Answer 3

等于运算符仅适用于单个值，而不适用于多个值，因此错误。因此，使用IN：

而不是等式

... WHERE id IN (SELECT ...)

Answer 4

UPDATE tbl1 SET Status = 'Finished' 
WHERE id **IN** (SELECT id 
FROM tbl1 
WHERE NOT EXISTS (SELECT id FROM tbl1_temp 
WHERE tbl1.id = tbl1_temp.id))

更新WHERE NOT EXISTS问题

4 个答案: