SQL> select emp.ename, emp.sal, dept.dname 2 from emp, dept 3 where emp.deptno = dept.deptno; ENAME SAL DNAME ---------- --------- -------------- KING 5000 ACCOUNTING BLAKE 2850 SALES CLARK 2450 ACCOUNTING JONES 2975 RESEARCH MARTIN 1250 SALES ALLEN 1600 SALES TURNER 1500 SALES JAMES 950 SALES WARD 1250 SALES FORD 3000 RESEARCH SMITH 800 RESEARCH SCOTT 3000 RESEARCH ADAMS 1100 RESEARCH MILLER 1300 ACCOUNTING 14 rows selected. SQL> select e.ename, e.sal, d.dname 2 from emp, dept 3 where e.deptno = d.deptno; where e.deptno = d.deptno * ERROR at line 3: ORA-00904: "D"."DEPTNO": invalid identifier SQL> select e.ename, e.sal, d.dnam 2 from emp e, dept d 3 where e.deptno = d.deptno; select e.ename, e.sal, d.dnam * ERROR at line 1: ORA-00904: "D"."DNAM": invalid identifier SQL> select e.ename, e.sal, d.dname 2 from emp e, dept d 3 where e.deptno = d.deptno; ENAME SAL DNAME ---------- --------- -------------- KING 5000 ACCOUNTING BLAKE 2850 SALES CLARK 2450 ACCOUNTING JONES 2975 RESEARCH MARTIN 1250 SALES ALLEN 1600 SALES TURNER 1500 SALES JAMES 950 SALES WARD 1250 SALES FORD 3000 RESEARCH SMITH 800 RESEARCH SCOTT 3000 RESEARCH ADAMS 1100 RESEARCH MILLER 1300 ACCOUNTING 14 rows selected. SQL> select * from garade 2 ; select * from garade * ERROR at line 1: ORA-00942: table or view does not exist SQL> select * from grade 2 ; select * from grade * ERROR at line 1: ORA-00942: table or view does not exist SQL> select e.ename, e.sal, s.grade 2 from emp e, salgrade s 3 where e.sal between s.losal and s.hisal; ENAME SAL GRADE ---------- --------- --------- SMITH 800 1 JAMES 950 1 ADAMS 1100 1 WARD 1250 2 MARTIN 1250 2 MILLER 1300 2 TURNER 1500 3 ALLEN 1600 3 CLARK 2450 4 BLAKE 2850 4 JONES 2975 4 FORD 3000 4 SCOTT 3000 4 KING 5000 5 14 rows selected. SQL> select * from emp; EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO --------- ---------- --------- --------- ----------- --------- --------- --------- 7839 KING PRESIDENT 17-NOV-1981 5000 10 7698 BLAKE MANAGER 7839 01-MAY-1981 2850 30 7782 CLARK MANAGER 7839 09-JUN-1981 2450 10 7566 JONES MANAGER 7839 02-APR-1981 2975 20 7654 MARTIN SALESMAN 7698 28-SEP-1981 1250 1400 30 7499 ALLEN SALESMAN 7698 20-FEB-1981 1600 300 30 7844 TURNER SALESMAN 7698 08-SEP-1981 1500 0 30 7900 JAMES CLERK 7698 03-DEC-1981 950 30 7521 WARD SALESMAN 7698 22-FEB-1981 1250 500 30 7902 FORD ANALYST 7566 03-DEC-1981 3000 20 7369 SMITH CLERK 7902 17-DEC-1980 800 20 7788 SCOTT ANALYST 7566 09-DEC-1982 3000 20 7876 ADAMS CLERK 7788 12-JAN-1983 1100 20 7934 MILLER CLERK 7782 23-JAN-1982 1300 10 14 rows selected. SQL> select * from salgrade; GRADE LOSAL HISAL --------- --------- --------- 1 700 1200 2 1201 1400 3 1401 2000 4 2001 3000 5 3001 9999 SQL> select * from dept; DEPTNO DNAME LOC --------- -------------- ------------- 10 ACCOUNTING NEW YORK 20 RESEARCH DALLAS 30 SALES CHICAGO 40 OPERATIONS BOSTON SQL> select e.ename pracownik, e1.ename szeff 2 from emp e, emp e1 3 where e.mgr = e1.empno; PRACOWNIK SZEFF ---------- ---------- JONES KING CLARK KING BLAKE KING WARD BLAKE JAMES BLAKE TURNER BLAKE ALLEN BLAKE MARTIN BLAKE MILLER CLARK SCOTT JONES FORD JONES SMITH FORD ADAMS SCOTT 13 rows selected. SQL> select e.ename pracownik, e1.ename szef 2 from emp e, emp e1 3 where e.mgr = e1.empno(+); PRACOWNIK SZEF ---------- ---------- JONES KING CLARK KING BLAKE KING WARD BLAKE JAMES BLAKE TURNER BLAKE ALLEN BLAKE MARTIN BLAKE MILLER CLARK SCOTT JONES FORD JONES SMITH FORD ADAMS SCOTT KING 14 rows selected. SQL> select e.deptno, d.deptno, d.dname 2 from emp e, dept d 3 where e.deptno != d.deptno; DEPTNO DEPTNO DNAME --------- --------- -------------- 30 10 ACCOUNTING 20 10 ACCOUNTING 30 10 ACCOUNTING 30 10 ACCOUNTING 30 10 ACCOUNTING 30 10 ACCOUNTING 30 10 ACCOUNTING 20 10 ACCOUNTING 20 10 ACCOUNTING 20 10 ACCOUNTING 20 10 ACCOUNTING 10 20 RESEARCH 30 20 RESEARCH 10 20 RESEARCH 30 20 RESEARCH 30 20 RESEARCH 30 20 RESEARCH 30 20 RESEARCH 30 20 RESEARCH 10 20 RESEARCH 10 30 SALES DEPTNO DEPTNO DNAME --------- --------- -------------- 10 30 SALES 20 30 SALES 20 30 SALES 20 30 SALES 20 30 SALES 20 30 SALES 10 30 SALES 10 40 OPERATIONS 30 40 OPERATIONS 10 40 OPERATIONS 20 40 OPERATIONS 30 40 OPERATIONS 30 40 OPERATIONS 30 40 OPERATIONS 30 40 OPERATIONS 30 40 OPERATIONS 20 40 OPERATIONS 20 40 OPERATIONS 20 40 OPERATIONS 20 40 OPERATIONS 10 40 OPERATIONS 42 rows selected. SQL> select e.deptno, d.deptno, d.dname 2 from emp e, dept d 3 where d.deptno = 40; DEPTNO DEPTNO DNAME --------- --------- -------------- 10 40 OPERATIONS 30 40 OPERATIONS 10 40 OPERATIONS 20 40 OPERATIONS 30 40 OPERATIONS 30 40 OPERATIONS 30 40 OPERATIONS 30 40 OPERATIONS 30 40 OPERATIONS 20 40 OPERATIONS 20 40 OPERATIONS 20 40 OPERATIONS 20 40 OPERATIONS 10 40 OPERATIONS 14 rows selected. SQL> select e.deptno, d.deptno, d.dname 2 from emp e, dept d 3 where d.deptno = 40 like 1; where d.deptno = 40 like 1 * ERROR at line 3: ORA-00933: SQL command not properly ended SQL> select e.deptno, d.deptno, d.dname 2 from emp e, dept dwhere 3 ; select e.deptno, d.deptno, d.dname * ERROR at line 1: ORA-00904: "D"."DNAME": invalid identifier SQL> select e.deptno, d.deptno, d.dname 2 from emp e, dept d 3 where d.deptno = e.deptno(+); DEPTNO DEPTNO DNAME --------- --------- -------------- 10 10 ACCOUNTING 30 30 SALES 10 10 ACCOUNTING 20 20 RESEARCH 30 30 SALES 30 30 SALES 30 30 SALES 30 30 SALES 30 30 SALES 20 20 RESEARCH 20 20 RESEARCH 20 20 RESEARCH 20 20 RESEARCH 10 10 ACCOUNTING 40 OPERATIONS 15 rows selected. SQL> select e.deptno, d.deptno, d.dname 2 from emp e, dept d 3 where d.deptno = e.deptno(+) and e.deptno is null; DEPTNO DEPTNO DNAME --------- --------- -------------- 40 OPERATIONS SQL> select e.eanme, e1.ename 2 from emp e, emp e1 3 where e.ename select e.ename, e1.ename 2 from emp e, emp e1 3 where e.ename select * from emp; EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO --------- ---------- --------- --------- ----------- --------- --------- --------- 7839 KING PRESIDENT 17-NOV-1981 5000 10 7698 BLAKE MANAGER 7839 01-MAY-1981 2850 30 7782 CLARK MANAGER 7839 09-JUN-1981 2450 10 7566 JONES MANAGER 7839 02-APR-1981 2975 20 7654 MARTIN SALESMAN 7698 28-SEP-1981 1250 1400 30 7499 ALLEN SALESMAN 7698 20-FEB-1981 1600 300 30 7844 TURNER SALESMAN 7698 08-SEP-1981 1500 0 30 7900 JAMES CLERK 7698 03-DEC-1981 950 30 7521 WARD SALESMAN 7698 22-FEB-1981 1250 500 30 7902 FORD ANALYST 7566 03-DEC-1981 3000 20 7369 SMITH CLERK 7902 17-DEC-1980 800 20 7788 SCOTT ANALYST 7566 09-DEC-1982 3000 20 7876 ADAMS CLERK 7788 12-JAN-1983 1100 20 7934 MILLER CLERK 7782 23-JAN-1982 1300 10 14 rows selected. SQL> select * from desc; select * from desc * ERROR at line 1: ORA-00903: invalid table name SQL> select * from dept; DEPTNO DNAME LOC --------- -------------- ------------- 10 ACCOUNTING NEW YORK 20 RESEARCH DALLAS 30 SALES CHICAGO 40 OPERATIONS BOSTON SQL> select * from salgrade; GRADE LOSAL HISAL --------- --------- --------- 1 700 1200 2 1201 1400 3 1401 2000 4 2001 3000 5 3001 9999 SQL> select e.ename, e.deptno, d.deptno, d.loc, g.grade 2 from emp e, dept d, salgrade g 3 ; ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- KING 10 10 NEW YORK 1 BLAKE 30 10 NEW YORK 1 CLARK 10 10 NEW YORK 1 JONES 20 10 NEW YORK 1 MARTIN 30 10 NEW YORK 1 ALLEN 30 10 NEW YORK 1 TURNER 30 10 NEW YORK 1 JAMES 30 10 NEW YORK 1 WARD 30 10 NEW YORK 1 FORD 20 10 NEW YORK 1 SMITH 20 10 NEW YORK 1 SCOTT 20 10 NEW YORK 1 ADAMS 20 10 NEW YORK 1 MILLER 10 10 NEW YORK 1 KING 10 10 NEW YORK 2 BLAKE 30 10 NEW YORK 2 CLARK 10 10 NEW YORK 2 JONES 20 10 NEW YORK 2 MARTIN 30 10 NEW YORK 2 ALLEN 30 10 NEW YORK 2 TURNER 30 10 NEW YORK 2 ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- JAMES 30 10 NEW YORK 2 WARD 30 10 NEW YORK 2 FORD 20 10 NEW YORK 2 SMITH 20 10 NEW YORK 2 SCOTT 20 10 NEW YORK 2 ADAMS 20 10 NEW YORK 2 MILLER 10 10 NEW YORK 2 KING 10 10 NEW YORK 3 BLAKE 30 10 NEW YORK 3 CLARK 10 10 NEW YORK 3 JONES 20 10 NEW YORK 3 MARTIN 30 10 NEW YORK 3 ALLEN 30 10 NEW YORK 3 TURNER 30 10 NEW YORK 3 JAMES 30 10 NEW YORK 3 WARD 30 10 NEW YORK 3 FORD 20 10 NEW YORK 3 SMITH 20 10 NEW YORK 3 SCOTT 20 10 NEW YORK 3 ADAMS 20 10 NEW YORK 3 MILLER 10 10 NEW YORK 3 ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- KING 10 10 NEW YORK 4 BLAKE 30 10 NEW YORK 4 CLARK 10 10 NEW YORK 4 JONES 20 10 NEW YORK 4 MARTIN 30 10 NEW YORK 4 ALLEN 30 10 NEW YORK 4 TURNER 30 10 NEW YORK 4 JAMES 30 10 NEW YORK 4 WARD 30 10 NEW YORK 4 FORD 20 10 NEW YORK 4 SMITH 20 10 NEW YORK 4 SCOTT 20 10 NEW YORK 4 ADAMS 20 10 NEW YORK 4 MILLER 10 10 NEW YORK 4 KING 10 10 NEW YORK 5 BLAKE 30 10 NEW YORK 5 CLARK 10 10 NEW YORK 5 JONES 20 10 NEW YORK 5 MARTIN 30 10 NEW YORK 5 ALLEN 30 10 NEW YORK 5 TURNER 30 10 NEW YORK 5 ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- JAMES 30 10 NEW YORK 5 WARD 30 10 NEW YORK 5 FORD 20 10 NEW YORK 5 SMITH 20 10 NEW YORK 5 SCOTT 20 10 NEW YORK 5 ADAMS 20 10 NEW YORK 5 MILLER 10 10 NEW YORK 5 KING 10 20 DALLAS 1 BLAKE 30 20 DALLAS 1 CLARK 10 20 DALLAS 1 JONES 20 20 DALLAS 1 MARTIN 30 20 DALLAS 1 ALLEN 30 20 DALLAS 1 TURNER 30 20 DALLAS 1 JAMES 30 20 DALLAS 1 WARD 30 20 DALLAS 1 FORD 20 20 DALLAS 1 SMITH 20 20 DALLAS 1 SCOTT 20 20 DALLAS 1 ADAMS 20 20 DALLAS 1 MILLER 10 20 DALLAS 1 ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- KING 10 20 DALLAS 2 BLAKE 30 20 DALLAS 2 CLARK 10 20 DALLAS 2 JONES 20 20 DALLAS 2 MARTIN 30 20 DALLAS 2 ALLEN 30 20 DALLAS 2 TURNER 30 20 DALLAS 2 JAMES 30 20 DALLAS 2 WARD 30 20 DALLAS 2 FORD 20 20 DALLAS 2 SMITH 20 20 DALLAS 2 SCOTT 20 20 DALLAS 2 ADAMS 20 20 DALLAS 2 MILLER 10 20 DALLAS 2 KING 10 20 DALLAS 3 BLAKE 30 20 DALLAS 3 CLARK 10 20 DALLAS 3 JONES 20 20 DALLAS 3 MARTIN 30 20 DALLAS 3 ALLEN 30 20 DALLAS 3 TURNER 30 20 DALLAS 3 ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- JAMES 30 20 DALLAS 3 WARD 30 20 DALLAS 3 FORD 20 20 DALLAS 3 SMITH 20 20 DALLAS 3 SCOTT 20 20 DALLAS 3 ADAMS 20 20 DALLAS 3 MILLER 10 20 DALLAS 3 KING 10 20 DALLAS 4 BLAKE 30 20 DALLAS 4 CLARK 10 20 DALLAS 4 JONES 20 20 DALLAS 4 MARTIN 30 20 DALLAS 4 ALLEN 30 20 DALLAS 4 TURNER 30 20 DALLAS 4 JAMES 30 20 DALLAS 4 WARD 30 20 DALLAS 4 FORD 20 20 DALLAS 4 SMITH 20 20 DALLAS 4 SCOTT 20 20 DALLAS 4 ADAMS 20 20 DALLAS 4 MILLER 10 20 DALLAS 4 ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- KING 10 20 DALLAS 5 BLAKE 30 20 DALLAS 5 CLARK 10 20 DALLAS 5 JONES 20 20 DALLAS 5 MARTIN 30 20 DALLAS 5 ALLEN 30 20 DALLAS 5 TURNER 30 20 DALLAS 5 JAMES 30 20 DALLAS 5 WARD 30 20 DALLAS 5 FORD 20 20 DALLAS 5 SMITH 20 20 DALLAS 5 SCOTT 20 20 DALLAS 5 ADAMS 20 20 DALLAS 5 MILLER 10 20 DALLAS 5 KING 10 30 CHICAGO 1 BLAKE 30 30 CHICAGO 1 CLARK 10 30 CHICAGO 1 JONES 20 30 CHICAGO 1 MARTIN 30 30 CHICAGO 1 ALLEN 30 30 CHICAGO 1 TURNER 30 30 CHICAGO 1 ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- JAMES 30 30 CHICAGO 1 WARD 30 30 CHICAGO 1 FORD 20 30 CHICAGO 1 SMITH 20 30 CHICAGO 1 SCOTT 20 30 CHICAGO 1 ADAMS 20 30 CHICAGO 1 MILLER 10 30 CHICAGO 1 KING 10 30 CHICAGO 2 BLAKE 30 30 CHICAGO 2 CLARK 10 30 CHICAGO 2 JONES 20 30 CHICAGO 2 MARTIN 30 30 CHICAGO 2 ALLEN 30 30 CHICAGO 2 TURNER 30 30 CHICAGO 2 JAMES 30 30 CHICAGO 2 WARD 30 30 CHICAGO 2 FORD 20 30 CHICAGO 2 SMITH 20 30 CHICAGO 2 SCOTT 20 30 CHICAGO 2 ADAMS 20 30 CHICAGO 2 MILLER 10 30 CHICAGO 2 ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- KING 10 30 CHICAGO 3 BLAKE 30 30 CHICAGO 3 CLARK 10 30 CHICAGO 3 JONES 20 30 CHICAGO 3 MARTIN 30 30 CHICAGO 3 ALLEN 30 30 CHICAGO 3 TURNER 30 30 CHICAGO 3 JAMES 30 30 CHICAGO 3 WARD 30 30 CHICAGO 3 FORD 20 30 CHICAGO 3 SMITH 20 30 CHICAGO 3 SCOTT 20 30 CHICAGO 3 ADAMS 20 30 CHICAGO 3 MILLER 10 30 CHICAGO 3 KING 10 30 CHICAGO 4 BLAKE 30 30 CHICAGO 4 CLARK 10 30 CHICAGO 4 JONES 20 30 CHICAGO 4 MARTIN 30 30 CHICAGO 4 ALLEN 30 30 CHICAGO 4 TURNER 30 30 CHICAGO 4 ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- JAMES 30 30 CHICAGO 4 WARD 30 30 CHICAGO 4 FORD 20 30 CHICAGO 4 SMITH 20 30 CHICAGO 4 SCOTT 20 30 CHICAGO 4 ADAMS 20 30 CHICAGO 4 MILLER 10 30 CHICAGO 4 KING 10 30 CHICAGO 5 BLAKE 30 30 CHICAGO 5 CLARK 10 30 CHICAGO 5 JONES 20 30 CHICAGO 5 MARTIN 30 30 CHICAGO 5 ALLEN 30 30 CHICAGO 5 TURNER 30 30 CHICAGO 5 JAMES 30 30 CHICAGO 5 WARD 30 30 CHICAGO 5 FORD 20 30 CHICAGO 5 SMITH 20 30 CHICAGO 5 SCOTT 20 30 CHICAGO 5 ADAMS 20 30 CHICAGO 5 MILLER 10 30 CHICAGO 5 ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- KING 10 40 BOSTON 1 BLAKE 30 40 BOSTON 1 CLARK 10 40 BOSTON 1 JONES 20 40 BOSTON 1 MARTIN 30 40 BOSTON 1 ALLEN 30 40 BOSTON 1 TURNER 30 40 BOSTON 1 JAMES 30 40 BOSTON 1 WARD 30 40 BOSTON 1 FORD 20 40 BOSTON 1 SMITH 20 40 BOSTON 1 SCOTT 20 40 BOSTON 1 ADAMS 20 40 BOSTON 1 MILLER 10 40 BOSTON 1 KING 10 40 BOSTON 2 BLAKE 30 40 BOSTON 2 CLARK 10 40 BOSTON 2 JONES 20 40 BOSTON 2 MARTIN 30 40 BOSTON 2 ALLEN 30 40 BOSTON 2 TURNER 30 40 BOSTON 2 ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- JAMES 30 40 BOSTON 2 WARD 30 40 BOSTON 2 FORD 20 40 BOSTON 2 SMITH 20 40 BOSTON 2 SCOTT 20 40 BOSTON 2 ADAMS 20 40 BOSTON 2 MILLER 10 40 BOSTON 2 KING 10 40 BOSTON 3 BLAKE 30 40 BOSTON 3 CLARK 10 40 BOSTON 3 JONES 20 40 BOSTON 3 MARTIN 30 40 BOSTON 3 ALLEN 30 40 BOSTON 3 TURNER 30 40 BOSTON 3 JAMES 30 40 BOSTON 3 WARD 30 40 BOSTON 3 FORD 20 40 BOSTON 3 SMITH 20 40 BOSTON 3 SCOTT 20 40 BOSTON 3 ADAMS 20 40 BOSTON 3 MILLER 10 40 BOSTON 3 ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- KING 10 40 BOSTON 4 BLAKE 30 40 BOSTON 4 CLARK 10 40 BOSTON 4 JONES 20 40 BOSTON 4 MARTIN 30 40 BOSTON 4 ALLEN 30 40 BOSTON 4 TURNER 30 40 BOSTON 4 JAMES 30 40 BOSTON 4 WARD 30 40 BOSTON 4 FORD 20 40 BOSTON 4 SMITH 20 40 BOSTON 4 SCOTT 20 40 BOSTON 4 ADAMS 20 40 BOSTON 4 MILLER 10 40 BOSTON 4 KING 10 40 BOSTON 5 BLAKE 30 40 BOSTON 5 CLARK 10 40 BOSTON 5 JONES 20 40 BOSTON 5 MARTIN 30 40 BOSTON 5 ALLEN 30 40 BOSTON 5 TURNER 30 40 BOSTON 5 ENAME DEPTNO DEPTNO LOC GRADE ---------- --------- --------- ------------- --------- JAMES 30 40 BOSTON 5 WARD 30 40 BOSTON 5 FORD 20 40 BOSTON 5 SMITH 20 40 BOSTON 5 SCOTT 20 40 BOSTON 5 ADAMS 20 40 BOSTON 5 MILLER 10 40 BOSTON 5 280 rows selected. SQL> select * from dept; DEPTNO DNAME LOC --------- -------------- ------------- 10 ACCOUNTING NEW YORK 20 RESEARCH DALLAS 30 SALES CHICAGO 40 OPERATIONS BOSTON SQL> select e.ename, d.loc, s.grade 2 from emp e, dept d, salgrade s 3 e.deptno = d.deptno and 4 d.log = 'dallas' and 5 s.grade between 2 and 4; e.deptno = d.deptno and * ERROR at line 3: ORA-00933: SQL command not properly ended SQL> select e.ename, d.loc, s.grad 2 from emp e, dept d, salgrade s 3 where e.deptno = d.deptno and 4 d.log = 'dallas' and 5 s.grade between 2 and 4; d.log = 'dallas' and * ERROR at line 4: ORA-00904: "D"."LOG": invalid identifier SQL> select e.ename, d.loc, s.grad 2 from emp e, dept d, salgrade s 3 where e.deptno = d.deptno an 4 d.loc = 'dallas' and 5 s.grade between 2 and 4; where e.deptno = d.deptno an * ERROR at line 3: ORA-00933: SQL command not properly ended SQL> select e.ename, d.loc, s.grad 2 from emp e, dept d, salgrade s 3 where e.deptno = d.deptno and 4 d.loc = 'dallas' and 5 s.grade between 2 and 4; select e.ename, d.loc, s.grad * ERROR at line 1: ORA-00904: "S"."GRAD": invalid identifier SQL> select e.ename, d.loc, s.grade 2 from emp e, dept d, salgrade s 3 where e.deptno = d.deptno and 4 d.loc = 'dallas' and 5 s.grade between 2 and 4; no rows selected SQL> select e.ename, d.loc, s.grade 2 from emp e, dept d, salgrade s 3 where e.deptno = d.deptno and 4 d.loc = 'DALLAS' and 5 s.grade between 2 and 4; ENAME LOC GRADE ---------- ------------- --------- JONES DALLAS 4 JONES DALLAS 3 JONES DALLAS 2 FORD DALLAS 4 FORD DALLAS 3 FORD DALLAS 2 SMITH DALLAS 4 SMITH DALLAS 3 SMITH DALLAS 2 SCOTT DALLAS 4 SCOTT DALLAS 3 SCOTT DALLAS 2 ADAMS DALLAS 4 ADAMS DALLAS 3 ADAMS DALLAS 2 15 rows selected. SQL> select * from emp; EMPNO ENAME JOB MGR HIREDATE SAL COMM DEPTNO --------- ---------- --------- --------- ----------- --------- --------- --------- 7839 KING PRESIDENT 17-NOV-1981 5000 10 7698 BLAKE MANAGER 7839 01-MAY-1981 2850 30 7782 CLARK MANAGER 7839 09-JUN-1981 2450 10 7566 JONES MANAGER 7839 02-APR-1981 2975 20 7654 MARTIN SALESMAN 7698 28-SEP-1981 1250 1400 30 7499 ALLEN SALESMAN 7698 20-FEB-1981 1600 300 30 7844 TURNER SALESMAN 7698 08-SEP-1981 1500 0 30 7900 JAMES CLERK 7698 03-DEC-1981 950 30 7521 WARD SALESMAN 7698 22-FEB-1981 1250 500 30 7902 FORD ANALYST 7566 03-DEC-1981 3000 20 7369 SMITH CLERK 7902 17-DEC-1980 800 20 7788 SCOTT ANALYST 7566 09-DEC-1982 3000 20 7876 ADAMS CLERK 7788 12-JAN-1983 1100 20 7934 MILLER CLERK 7782 23-JAN-1982 1300 10 14 rows selected. SQL> select e.ename, e1.ename 2 from emp e, emp e1 3 where e.mgr = e1.empno and 4 e.hiredate < e1.hiredate; ENAME ENAME ---------- ---------- JONES KING CLARK KING BLAKE KING WARD BLAKE ALLEN BLAKE SMITH FORD 6 rows selected. SQL> select avg(sal) 2 from emp; AVG(SAL) --------- 2073,2143 SQL> select avg(e.sal), d.dname 2 from emp e, dept d 3 where e.deptno = d.deptno; select avg(e.sal), d.dname * ERROR at line 1: ORA-00937: not a single-group group function SQL> select avg(e.sal), d.dname 2 from emp e, dept d 3 where e.deptno = d.deptno 4 group by d.dname; AVG(E.SAL) DNAME ---------- -------------- 2916,6667 ACCOUNTING 2175 RESEARCH 1566,6667 SALES SQL> select avg(e.sal), d.dname 2 from emp e, dept d 3 where e.deptno = d.deptno and 4 avg(e.sal) > 2500 5 group by d.dname; avg(e.sal) > 2500 * ERROR at line 4: ORA-00934: group function is not allowed here SQL> select avg(e.sal), d.danme 2 ; * ERROR at line 2: ORA-00923: FROM keyword not found where expected SQL> select avg(e.sal), d.dname 2 from emp e, dept d 3 where e.deptno = d.deptno 4 group by d.dname 5 having avg(e.sal)>2500; AVG(E.SAL) DNAME ---------- -------------- 2916,6667 ACCOUNTING SQL> select job, avg(sal) 2 from emp 3 group by job 4 having avg(sal)=(select min(avg(sal)) 5 from emp 6 group by job); JOB AVG(SAL) --------- --------- CLERK 1037,5 SQL> select ename, sal 2 from (select ename, sal 3 from emp 4 order by sal desc) 5 where rownum <=3; ENAME SAL ---------- --------- KING 5000 FORD 3000 SCOTT 3000 SQL>