MySQL 如何当值相同时获取特定行

要在值相同时获取特定行，请使用GROUP BY。首先创建一个表 –

mysql> create table DemoTable659(Id int,Name varchar(100),Score int);
Query OK，0 rows affected (0.52 sec)

使用insert命令在表中插入一些记录 –

mysql> insert into DemoTable659 values(11,'John',45);
Query OK，1 row affected (0.14 sec)
mysql> insert into DemoTable659 values(15,'John',59);
Query OK，1 row affected (0.20 sec)
mysql> insert into DemoTable659 values(15,'Sam',61);
Query OK，1 row affected (0.14 sec)

使用select语句显示表中的所有记录 –

mysql> select *from DemoTable659;

这将产生以下输出 –

+------+------+-------+
| Id   | Name | Score |
+------+------+-------+
|   11 | John |    45 |
|   15 | John |    59 |
|   15 | Sam  |    61 |
+------+------+-------+
3 rows in set (0.00 sec)

以下是在值相同时获取特定行的查询 –

mysql> select *from (select *from DemoTable659 order by Id desc) tbl group by Name;

这将产生以下输出 –

+------+------+-------+
| Id   | Name | Score |
+------+------+-------+
|   11 | John | 45    |
|   15 | Sam  | 61    |
+------+------+-------+
2 rows in set (0.04 sec)

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