Tag: technology

Quizzes (307) Questions (36705)

Questions Related to technology

Multiple choice technology databases

The EMP table contains these columns: LAST NAME VARCHAR2(25) SALARY NUMBER(6,2) DEPARTMENT_ID NUMBER(6) You need to display the employees who have not been assigned to any department. You write the SELECT statement: SELECT LAST_NAME, SALARY, DEPARTMENT_ID FROM EMP WHERE DEPARMENT_ID = NULL; What is true about this SQL statement?

  1. The SQL statement displays the desired results

  2. The column in the WHERE clause should be changed to display the desired results

  3. The operator in the WHERE clause should be changed to display the desired results

  4. The WHERE clause should be changed to use an outer join to display the desired results
Reveal answer Fill a bubble to check yourself
C Correct answer
Full explanation
Multiple choice technology databases

Which two statements about subqueries are true? (Choose two.)

  1. A single row subquery can retrieve data from only one table

  2. A SQL query statement cannot display data from table B that is referred to in its subquery, unless table B is included in the main query's FROM clause.

  3. A SQL query statement can display data from table B that is referred to in its subquery, without including table B in its own FROM clause.

  4. A single row subquery can retrieve data from more than one table

  5. A single row subquery cannot be used in a condition where the LIKE operator is used for comparison

  6. A multiple-row subquery cannot be used in a condition where the LIKE operator is used for comparison.
Reveal answer Fill a bubble to check yourself
B,D Correct answer
Full explanation
Multiple choice technology databases

CREATE TABLE dept(deptno NUMBER(2),dname VARCNAR2(14),1oc VARCNAR2 (13));ROLLBACK;DESCRIBE DEPTWhat is true about the set?

  1. The DESCRIBE DEPT statement displays the structure of the DEPT table

  2. The ROLLBACK statement frees the storage space occupies by the DEPT table

  3. The DESCRIBE DEPT statement returns an error ORA-04043: object DEPT does not exist

  4. The DESCRIBE DEPT statement displays the structure of the DEPT table only if there is a COMMIT statement introduced before the ROLLBACK statement.
Reveal answer Fill a bubble to check yourself
A Correct answer
Full explanation