SQL在每种情况下满足的条件？

Question

我有一个名为food

的示例表

item    id    date
apple   1     in-date
apple   1     in-date
banana  2     rotten
banana  2     in-date
lemon   3     in-date
lemon   3     in-date

我想编写一个只返回所有内容日期的项目的查询 即应归还苹果和柠檬。

我有，

select item
from food
where date = 'in-date';

然而，即使有些已经过时，这也会返回banana。 任何帮助将不胜感激

Answer 1

select distinct item
from food
where item not in (select item from food where date<>'in-date')

或者，如果您的SQL支持exists

select distinct item
from food
where not exists (select item from food f where date<>'in-date' and f.item=food.item )

Answer 2

SELECT item, SUM( CASE mydate WHEN 'in_date' THEN 0 ELSE 1 END ) as rotten
FROM food
GROUP BY item 
  HAVING rotten==0

Answer 3

尝试这样的事情： -

 select distinct item
 from food
 where not exists (select item from food f where date<>'in-date' and f.item=food.item )