Question

我有一个包含以下字段的mysql表

Transaction_id，toy_id，toy_name，Quantity_sold，Date_sold。

我想回答的问题是：今天卖的是什么玩具昨天没卖。我明白这是非常模糊的，所以请随意做出任何需要做的假设，以帮助把它写下来，谢谢你！

Answer 1

一种方法使用带有having子句的聚合：

select toy_id
from t
where date_sold >= date_sub(curdate(), interval 1 day)
group by toy_id
having date(min(date_sold)) = curdate();

where子句将数据限制为过去两天。如果最低日期是今天，那么昨天没有玩具出售。

Answer 2

您可以使用not exists运算符查找昨天未售出的玩具。 E.g：

SELECT toy_id, toy_name
FROM   transactions today
WHERE  date_sold = CURRENT_DATE()
       AND NOT EXISTS (SELECT *
                       FROM   transactions yesterday
                       WHERE  today.toy_id = yesterday.toy_id AND
                              yesterday.date_sold = 
                              today.date_solde - INTERVAL 1 DAY);

Answer 3

您可以使用not in和subselect

  Select Transaction_id, toy_id, toy_name, Quantity_sold, Date_sold
  from my_table  
  where to_id not in (
    select T toy_id 
    from my_table  
    where Date_sold = date(date_sub(now(), INTERVAL 1 day))
  );

自我比较事务表以查找值

3 个答案: