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 - Which of the following is not true about PL/SQL decision making structures?

A - The IF statement associates a condition with a sequence of statements enclosed by the keywords THEN and END IF.

B - The IF statement also adds the keyword ELSE followed by an alternative sequence of statement.

C - The IF-THEN-ELSIF statement allows you to choose between several alternatives.

D - PL/SQL does not have a CASE statement.

Q 4 - Consider the following code snippet: how many times the loop will run?

DECLARE
   a number(2) := 9;
BEGIN
   WHILE a < 30 LOOP
      a := a + 3;
   END LOOP;
END;

A - 10

B - 8

C - 7

D - 9

Q 5 - What would be the output of the following code?

DECLARE
   num number;
   fn number;

FUNCTION fx(x number)
RETURN number 
IS
   f number;
BEGIN
   IF x=0 THEN
      f := 1;
   ELSE
      f := x * fx(x-1);
   END IF;
RETURN f;
END;

BEGIN
   num:= 5;
   fn := fx(num);
   dbms_output.put_line(fn);
END;

A - 1

B - 5

C - 10

D - 125

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 not a benefit of a database trigger?

A - Enforcing referential integrity

B - Event logging and storing information on table access

C - Allowing invalid transactions

D - Generating some derived column values automatically

Q 8 - Which of the following statement will create the specification for a package named cust_sal

A -

CREATE PACKAGE BODY cust_sal AS
 PROCEDURE find_sal(c_id customers.id%type);
END cust_sal;

B -

CREATE PACKAGE cust_sal AS
 PROCEDURE find_sal(c_id customers.id%type);
END cust_sal;

C -

CREATE PACKAGE SPECIFICATION cust_sal AS
 PROCEDURE find_sal(c_id customers.id%type);
END cust_sal;

D -

PACKAGE cust_sal AS
 PROCEDURE find_sal(c_id customers.id%type);
END cust_sal;

Q 9 - Which of the following is true about PL/SQL nested tables?

A - Nested tables are like one-dimensional arrays with arbitrary number of elements.

B - Unlike arrays a nested table doesnt have declared number of elements. The size of a nested table can increase dynamically.

C - Initially a nested array has consecutive subscripts or dense, but it can become sparse when elements are deleted from it.

D - All of the above.

Q 10 - Which of the following is not true about the comparison methods?

A - These are used for comparing objects.

B - The Map method is a function implemented in such a way that its value doesnt depend upon the value of the attributes.

C - The Order methods implement some internal logic for comparing two objects.

D - None of the above.