現在一使用者表`user`，資料如下:

1.查出名稱`name`重複的記錄

mysql> select name, count(*) as name_count from user group by name having name_count > 1;

2.查出年齡`age`大於1，名稱`name`有多少種情況，分組:

mysql> select age, name, count(*) as cnt from user where age > 1 group by name;

3.查出年齡`age`大於1，名稱`name`重複的記錄

mysql> select age, name, count(*) as cnt from user where age > 1 group by name having cnt > 1;
 

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