PL/SQL - GOTO Statement

A GOTO statement in PL/SQL programming language provides an unconditional jump from the GOTO to a labeled statement in the same subprogram.

NOTE − The use of GOTO statement is not recommended in any programming language because it makes it difficult to trace the control flow of a program, making the program hard to understand and hard to modify. Any program that uses a GOTO can be rewritten so that it doesn't need the GOTO.

Syntax

The syntax for a GOTO statement in PL/SQL is as follows −

GOTO label;
..
..
<< label >>
statement;

Flow Diagram

Example

DECLARE 
   a number(2) := 10; 
BEGIN 
   <<loopstart>> 
   -- while loop execution  
   WHILE a < 20 LOOP
   dbms_output.put_line ('value of a: ' || a); 
      a := a + 1; 
      IF a = 15 THEN 
         a := a + 1; 
         GOTO loopstart; 
      END IF; 
   END LOOP; 
END; 
/

When the above code is executed at the SQL prompt, it produces the following result −

value of a: 10 
value of a: 11 
value of a: 12 
value of a: 13 
value of a: 14 
value of a: 16 
value of a: 17 
value of a: 18 
value of a: 19  

PL/SQL procedure successfully completed.

Restrictions with GOTO Statement

GOTO Statement in PL/SQL imposes the following restrictions −

• A GOTO statement cannot branch into an IF statement, CASE statement, LOOP statement or sub-block.

• A GOTO statement cannot branch from one IF statement clause to another or from one CASE statement WHEN clause to another.

• A GOTO statement cannot branch from an outer block into a sub-block (i.e., an inner BEGIN-END block).

• A GOTO statement cannot branch out of a subprogram. To end a subprogram early, either use the RETURN statement or have GOTO branch to a place right before the end of the subprogram.

• A GOTO statement cannot branch from an exception handler back into the current BEGIN-END block. However, a GOTO statement can branch from an exception handler into an enclosing block.