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40. 谁的工资比 Abel 高?1). 写两条 SQL 语句.SELECT salaryFROM employeesWHERE last_name = 'Abel'--返回值为 11000SELECT last_name, salaryFROM employeesWHERE salary > 110002). 使用子查询 -- 一条 SQL 语句SELECT last_name, salaryFROM employeesWHERE salary > (SELECT salaryFROM employeesWHERE last_name = 'Abel')子查询注意: 1). 子查询要包含在括号内2). 将子查询放在比较条件的右侧	41. 查询工资最低的员工信息: last_name, salary	42. 查询平均工资最低的部门信息43*. 查询平均工资最低的部门信息和该部门的平均工资44. 查询平均工资最高的 job 信息45. 查询平均工资高于公司平均工资的部门有哪些?46. 查询出公司中所有 manager 的详细信息.47. 各个部门中 最高工资中最低的那个部门的 最低工资是多少48. 查询平均工资最高的部门的 manager 的详细信息: last_name, department_id, email, salary49. 查询 1999 年来公司的人所有员工的最高工资的那个员工的信息./*************************************************************************************************/41. 查询工资最低的员工信息: last_name, salary	SELECT last_name, salaryFROM employeesWHERE salary = (SELECT min(salary)FROM employees)42. 查询平均工资最低的部门信息SELECT *FROM departmentsWHERE department_id = (SELECT department_idFROM employeesGROUP BY department_id HAVING avg(salary) = (SELECT min(avg(salary))FROM employeesGROUP BY department_id) )43. 查询平均工资最低的部门信息和该部门的平均工资select d.*, (select avg(salary) from employees where department_id = d.department_id)
from departments d
where d.department_id = (SELECT department_idFROM employeesGROUP BY department_id HAVING avg(salary) = (SELECT min(avg(salary))FROM employeesGROUP BY department_id) )44. 查询平均工资最高的 job 信息1). 按 job_id 分组, 查询最高的平均工资	SELECT max(avg(salary))FROM employeesGROUP BY job_id2). 查询出平均工资等于 1) 的 job_idSELECT job_idFROM employeesGROUP BY job_idHAVING avg(salary) = (SELECT max(avg(salary))FROM employeesGROUP BY job_id)3). 查询出 2) 对应的 job 信息SELECT *FROM jobsWHERE job_id = (SELECT job_idFROM employeesGROUP BY job_idHAVING avg(salary) = (SELECT max(avg(salary))FROM employeesGROUP BY job_id))45. 查询平均工资高于公司平均工资的部门有哪些?1). 查询出公司的平均工资SELECT avg(salary)FROM employees2). 查询平均工资高于 1) 的部门 IDSELECT department_idFROM employeesGROUP BY department_idHAVING avg(salary) > (SELECT avg(salary)FROM employees)46. 查询出公司中所有 manager 的详细信息.1). 查询出所有的 manager_idSELECT distinct manager_idFROM employeess2). 查询出 employee_id 为 1) 查询结果的那些员工的信息SELECT employee_id, last_nameFROM employeesWHERE employee_id in (SELECT distinct manager_idFROM employees)47. 各个部门中 最高工资中最低的那个部门的 最低工资是多少1). 查询出各个部门的最高工资SELECT max(salary)FROM employeesGROUP BY department_id2). 查询出 1) 对应的查询结果的最低值: 各个部门中最低的最高工资(无法查询对应的 department_id)SELECT min(max(salary))FROM employeesGROUP BY department_id3). 查询出 2) 所对应的部门 id 是多少: 各个部门中最高工资等于 2) 的那个部门的 idSELECT department_idFROM employeesGROUP BY department_id HAVING max(salary) = (SELECT min(max(salary))FROM employeesGROUP BY department_id)4). 查询出 3) 所在部门的最低工资SELECT min(salary)FROM employeesWHERE department_id = (SELECT department_idFROM employeesGROUP BY department_id HAVING max(salary) = (SELECT min(max(salary))FROM employeesGROUP BY department_id)	)48. 查询平均工资最高的部门的 manager 的详细信息: last_name, department_id, email, salary1). 各个部门中, 查询平均工资最高的平均工资是多少SELECT max(avg(salary))FROM employeesGROUP BY department_id2). 各个部门中, 平均工资等于 1) 的那个部门的部门号是多少SELECT department_idFROM employeesGROUP BY department_idHAVING avg(salary) = (SELECT max(avg(salary))FROM employeesGROUP BY department_id)3). 查询出 2) 对应的部门的 manager_idSELECT manager_idFROM departmentsWHERE department_id = (SELECT department_idFROM employeesGROUP BY department_idHAVING avg(salary) = (SELECT max(avg(salary))FROM employeesGROUP BY department_id)	)4). 查询出 employee_id 为 3) 查询的 manager_id 的员工的 last_name, department_id, email, salarySELECT last_name, department_id, email, salaryFROM employeesWHERE employee_id = (SELECT manager_idFROM departmentsWHERE department_id = (SELECT department_idFROM employeesGROUP BY department_idHAVING avg(salary) = (SELECT max(avg(salary))FROM employeesGROUP BY department_id)	)	)49. 查询 1999 年来公司的人所有员工的最高工资的那个员工的信息.1). 查询出 1999 年来公司的所有的员工的 salarySELECT salaryFROM employeesWHERE to_char(hire_date, 'yyyy') = '1999'2). 查询出 1) 对应的结果的最大值SELECT max(salary)FROM employeesWHERE to_char(hire_date, 'yyyy') = '1999'3). 查询工资等于 2) 对应的结果且 1999 年入职的员工信息		SELECT *FROM employeesWHERE to_char(hire_date, 'yyyy') = '1999' AND salary = (SELECT max(salary)FROM employeesWHERE to_char(hire_date, 'yyyy') = '1999')50. 多行子查询的 any 和 allselect department_idfrom employeesgroup by department_idhaving avg(salary) >= any(--所有部门的平均工资select avg(salary)from employeesgroup by department_id)any 和任意一个值比较, 所以其条件最为宽松, 所以实际上只需和平均工资最低的比较, 返回所有值
而 all 是和全部的值比较, 条件最为苛刻, 所以实际上返回的只需和平均工资最高的比较, 所以返回
平均工资最高的 department_id