sqlite - 结合两个sqlite语句

Question

如何将两个 sqlite 语句组合成一个？我只想要一个语句得到结果。

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，因为您正在分组code但选择date. 这是一个名为GROUP BY 和 HAVING 的 MySQL 扩展，带有隐藏列。如果您了解为什么此查询在大多数数据库中无效以及 MySQL 选择允许它的原因，您应该只使用此扩展。此查询很可能没有达到您的预期。