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如何在MySQL中获取表的第一条记录和最后一条记录？

2024-04-20 07:30:04 376

要获取第一条记录和最后一条记录，请使用UNION。LIMIT也用于获取所需的记录数。

让我们首先创建一个表-

mysql> create table DemoTable694 (
   EmployeeId int NOT NULL AUTO_INCREMENT PRIMARY KEY,
   EmployeeName varchar(100),
   EmployeeSalary int
);

使用插入命令在表中插入一些记录-

mysql> insert into DemoTable694(EmployeeName,EmployeeSalary) values('Chris',457647);
mysql> insert into DemoTable694(EmployeeName,EmployeeSalary) values('Robert',90883);
mysql> insert into DemoTable694(EmployeeName,EmployeeSalary) values('David',123532);
mysql> insert into DemoTable694(EmployeeName,EmployeeSalary) values('Mike',989322);

使用select语句显示表中的所有记录-

mysql> select *from DemoTable694;

这将产生以下输出-

+------------+--------------+----------------+
| EmployeeId | EmployeeName | EmployeeSalary |
+------------+--------------+----------------+
| 1          | Chris        | 457647         |
| 2          | Robert       | 90883          |
| 3          | David        | 123532         |
| 4          | Mike         | 989322         |
+------------+--------------+----------------+
4 rows in set (0.00 sec)

以下是获取第一个和最后一个记录的查询-

mysql> (select *from DemoTable694 order by EmployeeId ASC LIMIT 1)
UNION
(select *from DemoTable694 order by EmployeeId DESC LIMIT 1);

这将产生以下输出-

+------------+--------------+----------------+
| EmployeeId | EmployeeName | EmployeeSalary |
+------------+--------------+----------------+
| 1          | Chris        | 457647         |
| 4          | Mike         | 989322         |
+------------+--------------+----------------+
2 rows in set (0.00 sec)

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如何在MySQL中获取表的第一条记录和最后一条记录？

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