将 MySQL 查询转换为 PostgreSQL。按天排序（）？

Question

我正在将此代码从 MySQL 转换为 PostgreSQL。 PostgreSQL 没有 day() 函数让我的 Order by 工作。有已知的解决方案吗？我想按天对结果进行分组。

        {

        SELECT to_char(date, 'YYYY-mm-dd') AS date
        FROM \"users exercises\"
        WHERE userid = $user->id AND (date >= '$begin' AND date <= '$end')
        GROUP BY day(date)
        ORDER BY date

        ) UNION ALL (

        SELECT to_char(date, 'YYYY-mm-dd') AS date
        FROM \"users foods\"
        WHERE userid = $user->id AND (date >= '$begin' AND date <= '$end')
        GROUP BY day(date)
        ORDER BY date

        }

Answer 1

MySQL 的 day() returns 是一个月中的第几天。 PostgreSQL equivalent of that is:

GROUP BY extract(day from "date")

将 MySQL 查询转换为 PostgreSQL。按天排序（）？

Converting MySQL query to PostgreSQL. Order by day()?

sql

postgresql

sql-order-by