PL/SQL Boolean Examples

Question:  Can you please show an example of PL/SQL using the BOOLEAN datatype?  I need to see how the BOOLEAN is used in PL/SQL.

Answer:  Invented by George Boole (Boolean Logic), Boolean values are single byte datatypes that correspond to TRUE (1), FALSE (0) or NULL () values. 

For more working examples of Boolean values in PL/SQL see the code depot download in the book Easy Oracle PL/SQL Programming.

Boolean values are great for checking complex evaluations in PL/SQL.

A Boolean function can be wither a one (1) for TRUE and a zero (0) for FALSE:

function false return boolean
is
begin
return 0;
end;

function true return boolean
is
begin
return 1;
end;

---

Here is an example of a Boolean condition within a PL/SQL function:

create function
   credit_is_good
good_credit BOOLEAN := FALSE
 . . .
Return BOOLEAN
BEGIN
if complex IF/then else test > 500 then good_credit = := TRUE
END;

---

Here is another example of a Boolean operator in a PL/SQL stored procedure:

PROCEDURE profiler_control(
   start_stop IN VARCHAR2,
   run_comm IN VARCHAR2,
   ret OUT BOOLEAN) AS ret_code INTEGER;
BEGIN
 ret_code:=dbms_profiler.internal_version_check;
  IF ret_code !=0 THEN
   ret:=FALSE;
  ELSIF start_stop NOT IN ('START','STOP') THEN
   ret:=FALSE;
  ELSIF start_stop = 'START' THEN
   ret_code:=DBMS_PROFILER.START_PROFILER(run_comment1=>run_comm);
   IF ret_code=0 THEN
    ret:=TRUE;
   ELSE
    ret:=FALSE;
   END IF;
  ELSIF start_stop = 'STOP' THEN
   ret_code:=DBMS_PROFILER.FLUSH_DATA;
   ret_code:=DBMS_PROFILER.STOP_PROFILER;
   IF ret_code=0 THEN
    ret:=TRUE;
   ELSE
    ret:=FALSE;
   END IF;
  END IF;
END profiler_control;

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