sql的distinct有哪些替代方法

使用GROUP BY语句来实现去重功能：

SELECT column1, column2FROM table_nameGROUP BY column1, column2;

SELECT column1, column2FROM table_nameWHERE (column1, column2) IN (    SELECT DISTINCT column1, column2    FROM table_name);

SELECT DISTINCT column1, column2FROM (    SELECT column1, column2, ROW_NUMBER() OVER (PARTITION BY column1, column2 ORDER BY column1) AS rn    FROM table_name) AS subqueryWHERE rn = 1;