新人报道，求解SQL

select e.empname,
       e.empsal,
       (select sal.salclass
          from sal
         where e.empsal between sal.minsal and sal.maxsal) as 级别,
       (select count(*)
          from emp
         where emp.empsal between
               (select sal.minsal
                  from sal
                 where sal.salclass =
                       (select sal.salclass
                          from sal
                         where e.empsal between sal.minsal and sal.maxsal))
           and (select sal.maxsal
                  from sal
                 where sal.salclass =
                       (select sal.salclass
                          from sal
                         where e.empsal between sal.minsal and sal.maxsal))) as 人数,
       (select avg(emp.empsal)
          from emp
         where emp.empsal between
               (select sal.minsal
                  from sal
                 where sal.salclass =
                       (select sal.salclass
                          from sal
                         where e.empsal between sal.minsal and sal.maxsal))
           and (select sal.maxsal 
 
                  from sal
                 where sal.salclass =
                       (select sal.salclass
                          from sal
                         where e.empsal between sal.minsal and sal.maxsal))) as 平均
  from emp e
 where e.empid = 1