首页主机资讯mysql select去重的五种方法

mysql select去重的五种方法

时间2024-06-25 19:26:03发布访客分类主机资讯浏览300
导读:使用DISTINCT关键字 SELECT DISTINCT column_name FROM table_name; 使用GROUP BY子句 SELECT column_name FROM table_name GROUP BY c...

  1. 使用DISTINCT关键字

SELECT DISTINCT column_name FROM table_name;

  1. 使用GROUP BY子句

SELECT column_name FROM table_name GROUP BY column_name;

  1. 使用子查询

SELECT column_name FROM table_name WHERE column_name IN (SELECT DISTINCT column_name FROM table_name);

  1. 使用HAVING子句

SELECT column_name FROM table_name GROUP BY column_name HAVING COUNT(column_name) = 1;

  1. 使用临时表

CREATE TEMPORARY TABLE temp_table AS SELECT DISTINCT column_name FROM table_name; SELECT * FROM temp_table;

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