[打卡]子查询2

#单行子查询

#单行操作符

#习题：查询工资大于149号员工工资的员工信息
SELECT last_name,salary,department_id
FROM employees
WHERE salary >(
SELECT salary
FROM employees
WHERE employee_id = 149
);

#习题：返回job_id与141号员工相同，salary比143号员工多的员工姓名，job_id和工资
SELECT last_name,job_id,salary
FROM employees
WHERE job_id =(
SELECT job_id
FROM employees
WHERE employee_id = 141
)
AND salary > (
SELECT salary
FROM employees
WHERE employee_id = 143
);


#中英互换

#习题：返回公司工资最少的员工的last_name,job_id,salary
SELECT last_name,job_id,salary
FROM employees
WHERE salary = (
SELECT MIN(salary)
FROM employees
);
/*
子查询编写技巧（步骤）
1 从里往外写

2从外往里写

*/
#习题 ：查询与141号员工的manager_id和department_id相同的其他员工的employee_id,manager_id,department_id
SELECT employee_id,manager_id,department_id
FROM employees
WHERE manager_id =(
SELECT manager_id
FROM employees
WHERE employee_id = 141
)
AND department_id =(
SELECT department_id
FROM employees
WHERE employee_id = 141
)
AND employee_id <>141;

#方式2:
SELECT employee_id,manager_id,department_id
FROM employees
WHERE (manager_id,department_id) = (
SELECT manager_id,department_id
FROM employees
WHERE employee_id = 141
)
AND employee_id <>141;

#习题：查询最低工资大于60号部门最低工资的部门id和其最低工资

SELECT department_id,MIN(salary)
FROM employees
GROUP BY department_id
HAVING MIN(salary)>(
SELECT MIN(salary)
FROM employees
WHERE department_id = 60
)
AND department_id IS NOT NULL;


SELECT MIN(salary)
FROM employees
WHERE department_id = 110

#非法使用子查询

SELECT employee_id,last_name
FROM employees
WHERE salary =(
SELECT MIN(salary)
FROM employees
GROUP BY department_id
);