Question

如何将两个sqlite语句组合成一个？我只想要一个语句来获得结果。

create table lowprice as select  code,date,min(close) as min_close from quote where date between '20120730' and '20121030' group by code;
select  * from lowprice where lowprice.date between  '20121025'  and  '20121030' ;

Answer 1

您可以使用派生表（子查询）而不是创建实际表：

SELECT code, date, min_close
FROM
(
    SELECT code, date, min(close) as min_close
    from quote
    WHERE date BETWEEN '20120730' AND '20121030'
    GROUP BY code
) AS lowprice
WHERE lowprice.date BETWEEN '20121025' AND '20121030' ;

但是，此查询看起来很可疑，因为您按code进行分组，但选择date。这是一个名为GROUP BY and HAVING with hidden columns的MySQL扩展。如果你理解为什么这个查询在大多数数据库中无效以及MySQL选择允许它的原因，你应该只使用这个扩展。这个查询很可能没有达到预期效果。

结合两个sqlite语句

1 个答案: