Question

如果在where语句中我试图获取datetime大于NOW（）的所有行，但是如果type ='economy'，我想约束它只显示datetime和NOW之间的datediff（）大于14天。

类似：

Select type,date(datetime) as date
from tbl1
where datetime > NOW()
IF(type = 'economy') && datediff(datetime,NOW()) > 14
order by datetime desc

我也曾尝试过案例，但无法弄清楚......

Answer 1

您可以将标准分为两种不同的比较：

select type,date(datetime) as date 
from tbl1 
where (datetime > NOW() AND type <> 'economy') OR
      (datediff(datetime, NOW()) > 14 AND type = 'economy')
order by datetime desc

（未检查语法错误，但想法应该是正确的......）

Answer 2

WHERE ((type <> 'economy') AND (datetime > now)) OR ((type = 'economy') AND (datediff(datetime,NOW()) > 14)

Answer 3

SELECT type, date(datetime) AS date 
FROM tbl1 
WHERE ( type <> 'economy' AND datetime > NOW() ) 
    OR ( type = 'economy' AND datediff(datetime, NOW()) > 14 )

在where子句中使用if语句

3 个答案: