GROUP BY结合HAVING实现查询重复数据

GROUP BY 字段名，以该字段名已经分类，HAVING可以对分完类的数据使用聚合函数

例如

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1 2	SELECT *  FROM student  WHERE  stu_name IN (SELECT stu_name  FROM  student GROUP BY stu_name HAVING COUNT(stu_name)>1)

　　

 

 例如

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SELECT *  FROM student  WHERE  id IN ( SELECT id  FROM  student GROUP BY id HAVING MAX(id)>3 )

　　

 

 例如

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1	SELECT  *  FROM  student GROUP BY stu_name

　　

 

 相关sql

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CREATE TABLE student(  `id` INT(11)  PRIMARY KEY AUTO_INCREMENT COMMENT '主键',  stu_name VARCHAR(50) COMMENT '学生名称',  stu_id VARCHAR(20) COMMENT '学生编号' ) SELECT  *  FROM  student INSERT INTO student(stu_name,stu_id) VALUE ('小六','A1000'), ('小六','A1001'), ('小白','A1002'), ('小白','A1003'), ('小红','A1004'), ('小黑','A1005'), ('丸子','A1006'), ('静香','A1007')