Practical 5
1. Select statements

SELECT lastname, job, salary FROM Emp NATURAL JOIN Proj ON proj = projname WHEREprojname LIKE '%Design%';a wrong

1)
Correct:
CREATE VIEW qn1 AS SELECT lastname, job, salary FROM Emp JOIN Proj ON empno=respemp WHERE projname LIKE '%Design%';

2)

SELECT a.lastname, a.job, a.edlevel FROM Emp b JOIN Emp a ON b.edlevel <= a.edlevel WHERE a.job LIKE 'Pres%';

Correct:
CREATE VIEW qn2 AS SELECT b.lastname, b.job, b.edlevel FROM Emp a JOIN Emp b ON b.edlevel >= a.edlevel WHERE a.job = 'Pres';

3)

CREATE VIEW qn3 AS SELECT max(salary), min(salary), job FROM Emp GROUP BY job;

4)

SELECT AVG(Salary) FROM EMP WHERE COUNT(empno) > 10;

CREATE VIEW qn4 AS SELECT AVG(Salary), workdept, COUNT(empno) FROM Emp GROUP BY workdept HAVING COUNT(empno) > 5;