ANS. SELECT ENAME,SAL, DEPTNO, AVG(SAL)
FROM EMP
GROUP BY ENAME, SAL, DEPTNO;
29. MR. KING IS THE PRESIDENT OF A COMPANY. FIVE MANAGER REPORT TO HIM. ALL OTHER EMPLOYEES REPORT TO THESE MANAGERS.
EXAMINE THIS CODE:
SELECT EMPLOYEE.ENAME
FROM EMP.EMPLOYEE
WHERE EMPLOYEE, EMPNO NOT IN (SELECT MANAGER.MGR
FROM EMP MANAGER);
THE ABOVE STATEMENT RETURNS NO ROWS SELECTED AS THE RESULT WHY?
ANS.: A NULL VALUE IS RETURNED FROM THE SUB QUERY
30. WHICH STATEMENT ABOUT MULTIPLE COLUMN SUBQUERIES IS TRUE?
ANS: A NON-PAIR WISE COMPARISON PRODUCES A CROSS PRODUCT
31. THE EMPLOYEE TABLE CONTAINS THESE COLUMNS
FIRST_NAME VARCHAR2(25)
LAST_NAME VARCHAR2(25)
EVALUATE THESE TWO SQL STATEMENT
SELECT CONTACT(FIRST_NAME, LAST_NAME),
LENGTH(CONTACT (FIRST_NAME, LAST_NAME))
FROM EMPLOYEE
WHERE UPPER(LAST_NAME) LIKE ‘%J%’
OR UPPER(LAST_NAME) LIKE ‘%K%’
OR UPPER(LAST_NAME) LIKE ‘%L%’
SELECT INTCAP(FIRST)NAME),
INITCAP(LAST_NAME),
LENGTH(LAST_NAME) + LENGTH(FIRST_NAME) FROM EMPLOYEE