Dynamic Where Clause in Oracle 11g stored procedures

Introduction
It's been a long time since I'm using stored procedures in both Oracle and SQL server to do my programmings and this is what all other programmers are doing too. But when we move everything in spc, then sometimes we need to do search inside our spc too and return the result. So I was asking my own how I can generate an spc in Oracle that recieves parameters from caller and does a dynamic search based on what is passed to.
Certainly, I need to have a flexible dynamic WHERE at the end of my spc that has to be generated based on input parameters.
The following example shows how easily we are able to do this.

Please pay attention:
● Oracle is not case sensitive and this type of coding is just for reading it better.
● In this example, we have two parameters, a numeric and a string. If Numeric parameter be >0 then it will be used inside the where clause and also if the string one has a length greater than zero then it will be used inside where clause too
● Result will be returned as sys_refcursor

Using the code
This is very simple code and I think it is not needed to be described.

create or replace PROCEDURE   SP_MyProc
( Para_01_IN IN  NUMBER,     Para_02_IN In Nvarchar2 ,RESULT_OUT OUT sys_refcursor  )
IS 
 Begin 
 declare
 SelectClause       clob; --this will save the dynamic sql statement of search
  whereClause       clob;
    begin
    SelectClause:='';
    whereClause:='';
    SelectClause:=' select * from MyTable';
    whereClause := ' where {FixedConditionsHere} '
--Generating dynamic conditions
  if Para_01_IN != 0 then
          whereClause:=whereClause || ' and Para_01=   '|| to_char(Para_01_IN);
      end if;
      if LENGTH(Para_02 ) > 0  then
          whereClause:=whereClause||' and Para_02  ='||Para_02_IN ;
      end if;
-- This will open the cursor dynamically based on generated SQL commands 
       open RESULT_OUT for   SelectClause||whereClause ;--using whereClause;
       commit;
       end;
   EXCEPTION    WHEN OTHERS THEN  
 RAISE_APPLICATION_ERROR (-20001,'Error code ' || SQLCODE || ': ' || SUBSTR(SQLERRM, 1 , 200));
End;

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