1z0-051 Oracle Database 11g SQL Fundamentals Practice Exam

Sample Questions:

Evaluate the SQL statement:

TRUNCATE TABLE DEPT;

Which three are true about the SQL statement? (Choose three.)

It releases the storage space used by the table.

It does not release the storage space used by the table.

You can roll back the deletion of rows after the statement executes.

You can NOT roll back the deletion of rows after the statement executes.

An attempt to use DESCRIBE on the DEPT table after the TRUNCATE statement executes will display an error.

You must be the owner of the table or have DELETE ANY TABLE system privileges to truncate the DEPT table

You need to design a student registration database that contains several tables storing academic information.

The STUDENTS table stores information about a student. The STUDENT_GRADES table stores information about the student’s grades. Both of the tables have a column named STUDENT_ID. The STUDENT_ID column in the STUDENTS table is a primary key. You need to create a foreign key on the STUDENT_ID column of the STUDENT_GRADES table that points to the STUDENT_ID column of the STUDENTS table. Which statement creates the foreign key?

CREATE TABLE student_grades (student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT student_id_fk REFERENCES (student_id) FOREIGN KEY students(student_id));

CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), student_id_fk FOREIGN KEY (student_id) REFERENCES students(student_id));

CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT FOREIGN KEY (student_id) REFERENCES students(student_id));

CREATE TABLE student_grades(student_id NUMBER(12),semester_end DATE, gpa NUMBER(4,3), CONSTRAINT student_id_fk FOREIGN KEY (student_id) REFERENCES students(student_id));

Which three statements are true regarding sub queries? (Choose three.)

Multiple columns or expressions can be compared between the main query and sub query

Main query and sub query can get data from different tables

Sub queries can contain GROUP BY and ORDER BY clauses

Main query and sub query must get data from the same tables

Sub queries can contain ORDER BY but not the GROUP BY clause

Only one column or expression can be compared between the main query and subqeury

Evaluate these two SQL statements:

SELECT last_name, salary, hire_date FROM EMPLOYEES ORDER BY salary DESC;

SELECT last_name, salary, hire_date FROM EMPLOYEES ORDER BY 2 DESC;

What is true about them?

The two statements produce identical results.

The second statement returns a syntax error.

There is no need to specify DESC because the results are sorted in descending order by default.

The two statements can be made to produce identical results by adding a column alias for the salary column in the second SQL statement.