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法律研究找出 MySQL 员工表的最高薪水和第二高薪水
可以使用 LIMIT OFFSET 来从员工表获取最高工资和第二高的工资。语法如下所述 -
SELECT yourColumnName1,yourColumnName2,....N from yourTableName ORDER BY yourColumnName desc limit 2 offset 0;
为了理解上述语法，让我们创建一个表。创建表的查询如下所示 -
mysql> create table EmployeeMaxAndSecondMaxSalary -> ( -> EmployeeId int, -> Employeename varchar(20), -> EmployeeSalary int -> ); Query OK, 0 rows affected (0.88 sec)
使用 insert 命令向表中插入一些记录 -
mysql> insert into EmployeeMaxAndSecondMaxSalary values(1,'John',34566); Query OK, 1 row affected (0.20 sec) mysql> insert into EmployeeMaxAndSecondMaxSalary values(2,'Bob',56789); Query OK, 1 row affected (0.17 sec) mysql> insert into EmployeeMaxAndSecondMaxSalary values(3,'Carol',44560); Query OK, 1 row affected (0.26 sec) mysql> insert into EmployeeMaxAndSecondMaxSalary values(4,'Sam',76456); Query OK, 1 row affected (0.29 sec) mysql> insert into EmployeeMaxAndSecondMaxSalary values(5,'Mike',65566); Query OK, 1 row affected (0.14 sec) mysql> insert into EmployeeMaxAndSecondMaxSalary values(6,'David',89990); Query OK, 1 row affected (0.19 sec) mysql> insert into EmployeeMaxAndSecondMaxSalary values(7,'James',68789); Query OK, 1 row affected (0.12 sec) mysql> insert into EmployeeMaxAndSecondMaxSalary values(8,'Robert',76543); Query OK, 1 row affected (0.13 sec)
使用 select 语句显示表中的所有记录。查询如下所示 -
mysql> select *from EmployeeMaxAndSecondMaxSalary;
输出如下 -
+------------+--------------+----------------+ | EmployeeId | Employeename | EmployeeSalary | +------------+--------------+----------------+ | 1 | John | 34566 | | 2 | Bob | 56789 | | 3 | Carol | 44560 | | 4 | Sam | 76456 | | 5 | Mike | 65566 | | 6 | David | 89990 | | 7 | James | 68789 | | 8 | Robert | 76543 | +------------+--------------+----------------+ 8 rows in set (0.00 sec)
以下查询可使用 limit offset 获取最高和第二高的工资 -
mysql> select EmployeeId,Employeename,EmployeeSalary from EmployeeMaxAndSecondMaxSalary order by -> EmployeeSalary desc limit 2 offset 0;
输出显示 2 名最高工资员工的信息 -
+------------+--------------+----------------+ | EmployeeId | Employeename | EmployeeSalary | +------------+--------------+----------------+ | 6 | David | 89990 | | 8 | Robert | 76543 | +------------+--------------+----------------+ 2 rows in set (0.00 sec)
更新于: 30-6-2020
391 次浏览
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