sql - SQL 在每种情况下都满足条件吗？

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

我想编写一个查询，它只返回所有内容都在日期的项目，即应该返回苹果和柠檬。

我有，

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

banana但是，即使有些已过时，这也会返回。任何帮助将非常感激

score 7 · Accepted Answer

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 )

score 2 · Accepted Answer

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

score 1 · Accepted Answer

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 )

3 回答 3