PostgreSQL HAVING 子句

PostgreSQL HAVING 子句 HAVING 子句可以让我们筛选分组后的各组数据。 WHERE 子句在所选列上设置条件,而 HAVING 子句则在由 GROUP BY 子句创建的分组上设置条件。 语法 下面是 HAVING 子句在 SELECT 查询中的位置: SELECT FROM WHERE GROUP BY HAVING ORDER BY HAVING 子句必须放置于 GROUP BY 子句后面,ORDER BY 子句前面,下面是 HAVING 子句在 SELECT 语句中基础语法: SELECT column1, column2 FROM table1, table2 WHE