Question

我有一张如下表格：

| ID | Short Name | Long Name |
|----|------------|-----------|
| 1  | s1         | l2        |
| 2  | s1         | l2        |
| 3  | s1         | l2        |
| 4  | s5         | l6        |
| .. | ...        |           |

我希望获得所有共享相同短名称和长名称的记录。我需要他们共享的短名称，长名称和3个副本。标识。对于这个特例，我想要{s1，l2,1,2,3}

Answer 1

这是一个相当简单的问题需要解决。基本上您要做的是编写一个子查询，该子查询计算查询中每行在指定字段上匹配的行数。我在下面列举了几个例子。

查找所有重复的行并在两个名称字段上匹配

SELECT * FROM TableName WHERE (SELECT COUNT(*) FROM TableName AS T2 WHERE T2.ShortName = TableName.ShortName AND T2.LongName = TableName.LongName) > 1;

查找所有重复的行并在短名称上匹配

SELECT * FROM TableName WHERE (SELECT COUNT(*) FROM TableName AS T2 WHERE T2.ShortName = TableName.ShortName) > 1;

查找所有重复的行并在长名称上匹配

SELECT * FROM TableName WHERE (SELECT COUNT(*) FROM TableName AS T2 WHERE T2.LongName = TableName.LongName) > 1;

Answer 2

只需使用表格的自连接，然后选择两个名称相等且id不同的行：

SELECT * 
  FROM <table> t1, <table> t2
 WHERE t1.id        <> t2.id
   AND t1.short_name = t2.short_name
   AND t1.long_name  = t2.long_name;

Answer 3

您可以使用exits查看是否存在任何其他数据存在且ID不相同的相同条件。

select t1.* from table_name t1 
where exists (
  select 1 from table_name t2 
  where 
  t1.ID <> t2.ID 
  and t1.`Short Name` = t2.`Short Name` 
  and t1.`Long Name` = t2.`Long Name`
);

在表mysql中查找重复记录

3 个答案: