请教sql语句查询工资？

表创建： 1，员工表： DROP TABLE IF EXISTS `employee`; CREATE TABLE `employee` ( `emp_id` int(11) NOT NULL AUTO_INCREMENT, `dept_id` int(11) DEFAULT NULL, `emp_wage` int(11) DEFAULT NULL, PRIMARY KEY (`emp_id`) ) ENGINE=InnoDB AUTO_INCREMENT=6 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; 2，员工表数据： insert into `employee`(`emp_id`,`dept_id`,`emp_wage`) values (1,1,10000),(2,2,20000),(3,4,5000),(4,4,3000),(5,3,7500); 3，部门表： DROP TABLE IF EXISTS `department`; CREATE TABLE `department` ( `dept_id` int(11) NOT NULL AUTO_INCREMENT, `dept_name` varchar(50) COLLATE utf8_unicode_ci DEFAULT NULL, PRIMARY KEY (`dept_id`) ) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci; 4，部门表数据： insert into `department`(`dept_id`,`dept_name`) values (1,'信息部'),(2,'技术部'),(3,'外交部'),(4,'人事');-----------------------------------1) 求各部门的平均工资 select dept_name '部门名称',avg(emp_wage) "平均工资" from employee e left join department d on e.dept_id = d.dept_id GROUP BY emp_wage 2) 列出工资大于5000的员工所属部门名称、员工id和员工工资 select d.dept_name '部门名称',e.emp_id '员工id', e.emp_wage'员工工资' from employee e left join department d on e.dept_id=d.dept_id where e.emp_wage5000 group by d.dept_name,e.dept_id ,e.emp_id,e.emp_wage