mysql - mysql中的情况不起作用

Question

UPDATE a_timeblock SET timeblock_due_date=DATE(timeblock_next_update), 
CASE timeblock_recurrence_unit
 WHEN day THEN
       DATE_ADD(NOW(),INTERVAL timeblock_recurrence_time  day ) 
 WHEN month THEN
       DATE_ADD(NOW(),INTERVAL timeblock_recurrence_time  month) 
  END

 WHERE timeblock_recurrence=1 AND timeblock_complete=0 AND timeblock_next_update=    
 FROM_UNIXTIME(1337662800)

上面的查询是错误的。我想做类似上面的事情。如果可能的话，我该怎么做。

#1064 - You have an error in your SQL syntax; 
check the manual that corresponds to your MySQL 
server version for the right syntax to use near 
'CASE timeblock_recurrence_unit WHEN 'day' THEN DATE_ADD(NOW(),IN' at line 2

Answer 1

您的第二个值没有目标列。

UPDATE a_timeblock
SET timeblock_due_date = DATE(timeblock_next_update), 
    column_name?       = CASE ... END
WHERE ...

Answer 2

我认为您需要在案例中的值周围使用引号并简单地 SET timeblock_due_date：

...
SET timeblock_due_date =
CASE timeblock_recurrence_unit
  WHEN 'day' THEN
       DATE_ADD(NOW(),INTERVAL timeblock_recurrence_time  day ) 
  WHEN 'month' THEN
       DATE_ADD(NOW(),INTERVAL timeblock_recurrence_time  month) 
END
...

这假设timeblock_recurrence_unit是一个VARCHAR类型（它需要是）

Answer 3

可能是这样的？

UPDATE a_timeblock SET timeblock_due_date=
CASE timeblock_recurrence_unit
 WHEN 'day' THEN
       DATE_ADD(NOW(),INTERVAL timeblock_recurrence_time  day ) 
 WHEN 'month' THEN
       DATE_ADD(NOW(),INTERVAL timeblock_recurrence_time  month) 
  END

 WHERE timeblock_recurrence=1 AND timeblock_complete=0 AND timeblock_next_update=    
 FROM_UNIXTIME(1337662800)