Why do I get an error as I try to call a procedure? - oracle

Question

I created a procedure named greet as :
create procedure greet(message in char(50))
as
begin
dbms_output.put_line('Greet Message : ' || message);
end;
The procedure compiled successfully but when I try to call it as :
execute greet('Hey ! This is a self created procedure :)');
I get an error :
execute greet('Hey ! This is a self created procedure :)')
Error report:
ORA-06550: line 1, column 7:
PLS-00905: object SUHAIL.GREET is invalid
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored
06550. 00000 - "line %s, column %s:\n%s"
*Cause: Usually a PL/SQL compilation error.
*Action:
What error is it ? Why do I get it ?
Note : 'suhail' is name of the current user connected to oracle server

Answer 1

I don't believe that your procedure compiled successfully. When I try to compile it on my system, I get syntax errors
SQL> create procedure greet(message in char(50))
2 as
3 begin
4 dbms_output.put_line('Greet Message : ' || message);
5 end;
6 /
Warning: Procedure created with compilation errors.
SQL> sho err
Errors for PROCEDURE GREET:
LINE/COL ERROR
-------- -----------------------------------------------------------------
1/32 PLS-00103: Encountered the symbol "(" when expecting one of the
following:
:= ) , default varying character large
The symbol ":=" was substituted for "(" to continue.
If I resolve the syntax errors (you cannot specify a length for an input parameter), it works
SQL> ed
Wrote file afiedt.buf
1 create or replace procedure greet(message in char)
2 as
3 begin
4 dbms_output.put_line('Greet Message : ' || message);
5* end;
SQL> /
Procedure created.
SQL> set serveroutput on;
SQL> execute greet('Hey ! This is a self created procedure :)');
Greet Message : Hey ! This is a self created procedure :)
PL/SQL procedure successfully completed.
I would be shocked if you really wanted the input parameter to be declared as CHAR. Almost always, you should use VARCHAR2 for character strings. It is exceptionally rare to come across a case where you really want the blank-padding semantics of a CHAR.

Answer 2

this is working dude;
create or replace
procedure greet(message in char)
as
begin
dbms_output.put_line('Greet Message : ' || message);
end;
see main property of char datatype is is the length of input data is less than the size you specified it'll add blank spaces.this case is not happened for varchar2.
in procedure above mentioned char property is violated so it's almost treat like varchar2. so if you remove size of input parameter it will work and also char support maximum length of input.