create table dept(   
  deptno     number(2,0),   
  dname      varchar2(14),   
  loc        varchar2(13),   
  constraint pk_dept primary key (deptno)   
)
                        Table created.
create table emp(   
  empno    number(4,0),   
  ename    varchar2(10),   
  job      varchar2(9),   
  mgr      number(4,0),   
  hiredate date,   
  sal      number(7,2),   
  comm     number(7,2),   
  deptno   number(2,0),   
  constraint pk_emp primary key (empno),   
  constraint fk_deptno foreign key (deptno) references dept (deptno)   
)
                        Table created.
insert into DEPT (DEPTNO, DNAME, LOC) 
values(10, 'ACCOUNTING', 'NEW YORK')
                        1 row(s) inserted.
insert into dept   
values(20, 'RESEARCH', 'DALLAS')
                        1 row(s) inserted.
insert into dept   
values(30, 'SALES', 'CHICAGO')
                        1 row(s) inserted.
insert into dept  
values(40, 'OPERATIONS', 'BOSTON')
                        1 row(s) inserted.
insert into emp   
values(   
 7839, 'KING', 'PRESIDENT', null,   
 to_date('17-11-1981','dd-mm-yyyy'),   
 5000, null, 10   
)
                        1 row(s) inserted.
insert into emp  
values(  
 7698, 'BLAKE', 'MANAGER', 7839,  
 to_date('1-5-1981','dd-mm-yyyy'),  
 2850, null, 30  
)
                        1 row(s) inserted.
insert into emp  
values(  
 7782, 'CLARK', 'MANAGER', 7839,  
 to_date('9-6-1981','dd-mm-yyyy'),  
 2450, null, 10  
)
                        1 row(s) inserted.
insert into emp  
values(  
 7566, 'JONES', 'MANAGER', 7839,  
 to_date('2-4-1981','dd-mm-yyyy'),  
 2975, null, 20  
)
                        1 row(s) inserted.
insert into emp  
values(  
 7788, 'SCOTT', 'ANALYST', 7566,  
 to_date('13-JUL-87','dd-mm-rr') - 85,  
 3000, null, 20  
)
                        1 row(s) inserted.
insert into emp  
values(  
 7902, 'FORD', 'ANALYST', 7566,  
 to_date('3-12-1981','dd-mm-yyyy'),  
 3000, null, 20  
)
                        1 row(s) inserted.
insert into emp  
values(  
 7369, 'SMITH', 'CLERK', 7902,  
 to_date('17-12-1980','dd-mm-yyyy'),  
 800, null, 20  
)
                        1 row(s) inserted.
insert into emp  
values(  
 7499, 'ALLEN', 'SALESMAN', 7698,  
 to_date('20-2-1981','dd-mm-yyyy'),  
 1600, 300, 30  
)
                        1 row(s) inserted.
insert into emp  
values(  
 7521, 'WARD', 'SALESMAN', 7698,  
 to_date('22-2-1981','dd-mm-yyyy'),  
 1250, 500, 30  
)
                        1 row(s) inserted.
insert into emp  
values(  
 7654, 'MARTIN', 'SALESMAN', 7698,  
 to_date('28-9-1981','dd-mm-yyyy'),  
 1250, 1400, 30  
)
                        1 row(s) inserted.
insert into emp  
values(  
 7844, 'TURNER', 'SALESMAN', 7698,  
 to_date('8-9-1981','dd-mm-yyyy'),  
 1500, 0, 30  
)
                        1 row(s) inserted.
insert into emp  
values(  
 7876, 'ADAMS', 'CLERK', 7788,  
 to_date('13-JUL-87', 'dd-mm-rr') - 51,  
 1100, null, 20  
)
                        1 row(s) inserted.
insert into emp  
values(  
 7900, 'JAMES', 'CLERK', 7698,  
 to_date('3-12-1981','dd-mm-yyyy'),  
 950, null, 30  
)
                        1 row(s) inserted.
insert into emp  
values(  
 7934, 'MILLER', 'CLERK', 7782,  
 to_date('23-1-1982','dd-mm-yyyy'),  
 1300, null, 10  
)
                        1 row(s) inserted.
select ename, dname, job, empno, hiredate, loc   
from emp, dept   
where emp.deptno = dept.deptno   
order by ename
                        | ENAME | DNAME | JOB | EMPNO | HIREDATE | LOC | ADAMS | RESEARCH | CLERK | 7876 | 23-MAY-87 | DALLAS | ALLEN | SALES | SALESMAN | 7499 | 20-FEB-81 | CHICAGO | BLAKE | SALES | MANAGER | 7698 | 01-MAY-81 | CHICAGO | CLARK | ACCOUNTING | MANAGER | 7782 | 09-JUN-81 | NEW YORK | FORD | RESEARCH | ANALYST | 7902 | 03-DEC-81 | DALLAS | JAMES | SALES | CLERK | 7900 | 03-DEC-81 | CHICAGO | JONES | RESEARCH | MANAGER | 7566 | 02-APR-81 | DALLAS | KING | ACCOUNTING | PRESIDENT | 7839 | 17-NOV-81 | NEW YORK | MARTIN | SALES | SALESMAN | 7654 | 28-SEP-81 | CHICAGO | MILLER | ACCOUNTING | CLERK | 7934 | 23-JAN-82 | NEW YORK | SCOTT | RESEARCH | ANALYST | 7788 | 19-APR-87 | DALLAS | SMITH | RESEARCH | CLERK | 7369 | 17-DEC-80 | DALLAS | TURNER | SALES | SALESMAN | 7844 | 08-SEP-81 | CHICAGO | WARD | SALES | SALESMAN | 7521 | 22-FEB-81 | CHICAGO | 
|---|
select dname, count(*) count_of_employees 
from dept, emp 
where dept.deptno = emp.deptno 
group by DNAME 
order by 2 desc
                        | DNAME | COUNT_OF_EMPLOYEES | SALES | 6 | RESEARCH | 5 | ACCOUNTING | 3 | 
|---|