MariaDB select 仅结果大于

Question

我有一个如下所示的查询：

select uid,leadcount,salescount,leadcount/salescount as diff from 
(
SELECT x.uid, COUNT(*) leadcount, COUNT(DISTINCT x.fid)
FROM total_leads AS x
WHERE x.uid BETWEEN 1 AND 5
GROUP BY x.uid
) t1 left join 
(
SELECT ud.UserId, COUNT(*) salescount, COUNT(DISTINCT ud.SalesID)
FROM total_sales AS ud
WHERE ud.UserId BETWEEN 1 AND 5
GROUP BY ud.UserID
) t2 on t1.uid=t2.UserId

结果是：

我试图只显示 diff 大于 2.5 的结果（所以在这种情况下只有 uid 5 应该在输出中可见）。

我尝试使用 WHERE diff >= 2.5，但我得到了 "You have an error in your SQL syntax"。

Working example of MySQL

Answer 1

在MySQL和MariaDB中，你可以在查询的末尾添加一个HAVING子句：

HAVING diff >= 2.5

这类似于 WHERE 但可以使用别名。

Answer 2

只需在 WHERE 子句中重复原始表达式，而不是使用别名：

SELECT uid leadcount, salescount, leadcount/salescount AS diff
FROM
(
    ...
) t
WHERE leadcount/salescount >= 2.5;

在 WHERE 子句中引用 diff 的问题在于它尚不可用。另外，假设您不打算聚合，请参阅戈登的另一个选项的答案。但是，使用 HAVING 只是 MySQL 或 MariaDB 上的一个选项。

MariaDB select 仅结果大于

MariaDB select only results greater than

mysql

sql

mariadb

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