PL/SQL Online Quiz

Q 1 - Which of the following is not true about the declaration section of a PL/SQL block?

A - This section starts with the DECLARE keyword.

B - It is a mandatory section.

C - It defines all variables, cursors, subprograms, and other elements to be used in the program.

D - None of the above.

Q 2 - What is wrong in the following code?

DECLARE
   c_id := 1;
   c_name  customers.name%type;
   c_addr customers.address%type;
  BEGIN
   SELECT name, address INTO c_name, c_addr
   FROM customers
   WHERE id = c_id;
END;

A - You cannot use the SELECT INTO statement of SQL to assign values to PL/SQL variables.

B - The SELECT INTO statement here is wrong. It should be: SELECT c_name, c_address INTO name, addr

C - The WHERE statement is wrong. It should be: WHERE id := c_id;

D - The variable c_id should be declared as a type-compatible variable as −

c_id customers.id%type := 1;

Q 3 - What is the output of the following code?

DECLARE
   x number := 4;
BEGIN
   LOOP
      dbms_output.put_line(x);
      x := x + 1;
      exit WHEN x > 5;
   END LOOP;
      dbms_output.put_line(x);
END;

A - 4

     5

     6

B - 4

     5

C - 4

D - None of the above.

Q 4 - Which of the following is not true about the PL/SQL data structure VARRAY?

A - In oracle environment, the starting index for VARRAYs is always 1.

B - You can initialize the VARRAY elements using the constructor method of the VARRAY type, which has the same name as the VARRAY.

C - VARRAYs are one-dimensional arrays.

D - None of the above.

Q 5 - Observe the following code and fill in the blanks −

DECLARE 
   total_rows number(2);
BEGIN
   UPDATE employees
   SET salary = salary + 500;
   IF ____________ THEN
      dbms_output.put_line('no employees selected');
   ELSIF ___________ THEN
      total_rows := _____________;
      dbms_output.put_line( total_rows || ' employees selected ');
   END IF; 
END;

A - %notfound, %found, %rowcount.

B - sql%notfound, sql%found, sql%rowcount.

C - sql%found, sql%notfound, sql%rowcount.

D - %found, %notfound, %rowcount.

Q 6 - The following code tries to fetch some information from all the rows in a table named customers for use in a PL/SQL block. What is wrong in the following code?

DECLARE
   c_id customers.id%type;
   c_name customers.name%type;
   c_addr customers.address%type;
   CURSOR c_customers is
      SELECT id, name, address FROM customers;
BEGIN
   LOOP
      FETCH c_customers into c_id, c_name, c_addr;
      EXIT WHEN c_customers%notfound;
      dbms_output.put_line(c_id || ' ' || c_name || ' ' || c_addr);
   END LOOP;
   CLOSE c_customers;
END;

A - It need not use a cursor.

B - The cursor is not opened.

C - It will not print information from all the rows.

D - There is nothing wrong in the code.

Q 7 - Which of the following is true for querying a table in the same trigger?

A - The AFTER keyword should be used, because triggers can query the table or change it again only after the initial changes are applied and the table is back in a consistent state.

B - The BEFORE keyword should be used, because triggers can query the table or change it again only after the initial changes are applied and the table is back in a consistent state.

C - None of the points in a. and b.

D - Both of the points in a. and b.

Q 8 - Which of the following is true about PL/SQL index-by tables?

A - It is a set of key-value pairs.

B - Each key is unique and is used to locate the corresponding value.

C - The key can be either an integer or a string.

D - All of the above.

Q 9 - The collection method LIMIT

A - Returns the last (largest) index numbers in a collection that uses integer subscripts.

B - Returns the number of elements that a collection currently contains.

C - Checks the Maximum Size of a Collection.

D - None of the above.

Q 10 - Which of the following code will create an object type named local_address with two field house_no and street?

A -

CREATE OR REPLACE OBJECT local_address 
(house_no varchar2(10),
 street varchar2(30),
 );

B -

CREATE OR REPLACE TYPE local_address AS OBJECT
(house_no varchar2(10),
 street varchar2(30),
 );

C -

CREATE OR REPLACE OBJECT  local_address AS 
(house_no varchar2(10),
 street varchar2(30),
 );

D -

CREATE OR REPLACE CLASS local_address 
(house_no varchar2(10),
 street varchar2(30),
 );