sql的distinct有哪些替代方法

1. 使用GROUP BY语句来实现去重功能：

SELECT column1, column2
FROM table_name
GROUP BY column1, column2;

2. 使用子查询来实现去重功能：

SELECT column1, column2
FROM table_name
WHERE (column1, column2) IN (
    SELECT DISTINCT column1, column2
    FROM table_name
);

3. 使用窗口函数来实现去重功能：

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