Executing create or replace procedure statement from plsql script

Question

Hi ,
I want to execute create or replace procedure from pl/sql block without using execute immediate or dbms_sql, please let me know if feasible.
Eg:
declare
begin
create or replace procedure .....
if v_temp = 4 then
end if;
end;
Thanks for help.
Regards,
RK

Answer 1

user588487 wrote:
Actual requirement is I have .sql file which has Create procedure command in it
and i have to conditionally execute the above .sql file so going for a pl/sql block.
Eg:
begin
if variable1 <> variable2 then
@xyz.sql -- contains create or replace procedure statement
insert into tablexyz.....
end if;
end;
Won't work. The PL/SQL code block (also called an anonymous block) is shipped from the client (e.g. SQL*Plus) to the database server. There it is parsed and executed.
It cannot execute SQL*Plus code.
There are 2 basic approaches to address this requirement.
Method 1. Use PL/SQL and SQL to perform the conditional logic checks that SQL*Plus cannot. Use bind variables to "copy" the results between SQL*Plus and PL/SQL, use substitution variables to execute the conditional branch (as a script) in SQL*Plus.
Basic example:
SQL> --// bind variable for passing data to PL/SQL code and
SQL> --// to receive data from PL/SQL code
SQL> var status varchar2(100)
SQL>
SQL> declare
  2          function ExistsTable( tableName varchar2 ) return boolean is
  3                  i       integer;
  4          begin
  5                  select 1 into i
  6                  from    user_objects
  7                  where   object_type = 'TABLE'
  8                  and     object_name = tableName;
  9                  return( true );
10          exception when NO_DATA_FOUND then
11                  return( false );
12          end;
13  begin
14          --// determine if table exists
15          if not ExistsTable( 'FOOTAB' ) then
16                  --// table does not exists and SQL*Plus client
17                  --// needs to run the footab client script
18                  :status := 'footab.sql';
19          else
20                  :status := 'do-nothing.sql';
21          end if;
22  end;
23  /
PL/SQL procedure successfully completed.
SQL>
SQL> --// use a substitution variable to determine what to do
SQL> set define on
SQL> col STATUS new_value SCRIPT
SQL> select :status as STATUS from dual;
STATUS
footab.sql
SQL>
SQL> --// execute the relevant script (i.e. execute the conditional
SQL> --// branch of the PL/SQL IF condition
SQL> @ &SCRIPT
SQL> --// file: footab.sql
SQL>
SQL> create table footab(
  2          id      number primary key,
  3          col1    number,
  4          col2    date
  5  ) organization index
  6  /
Table created.
SQL>
SQL> --//eof
// running the same steps when the table does exist
SQL> --// bind variable for passing data to PL/SQL code and
SQL> --// to receive data from PL/SQL code
SQL> var status varchar2(100)
SQL>
SQL> declare
  2          function ExistsTable( tableName varchar2 ) return boolean is
  3                  i       integer;
  4          begin
  5                  select 1 into i
  6                  from    user_objects
  7                  where   object_type = 'TABLE'
  8                  and     object_name = tableName;
  9                  return( true );
10          exception when NO_DATA_FOUND then
11                  return( false );
12          end;
13  begin
14          --// determine if table exists
15          if not ExistsTable( 'FOOTAB' ) then
16                  --// table does not exists and SQL*Plus client
17                  --// needs to run the footab client script
18                  :status := 'footab.sql';
19          else
20                  :status := 'do-nothing.sql';
21          end if;
22  end;
23  /
PL/SQL procedure successfully completed.
SQL>
SQL> --// use a substitution variable to determine what to do
SQL> set define on
SQL> col STATUS new_value SCRIPT
SQL> select :status as STATUS from dual;
STATUS
do-nothing.sql
SQL>
SQL> --// execute the relevant script (i.e. execute the conditional
SQL> --// branch of the PL/SQL IF condition
SQL> @ &SCRIPT
SQL> prompt Nothing to do...
Nothing to do...
SQL> Method 2. Move all "client scripting" to the server. You can still use .sql files. These need to contain valid DDL that can be parsed and executed. On the server, the .sql files are loaded into a table.
This can be a physical load (e.g. using <i>DBMS_LOB.LoadFromFile()</i>). Or you can keep the .sql files on the server and use BFILE pointers instead to the files.
You can now use execute immediate to execute the contents of a .sql file as a CLOB that was read from the table containing the .sql scripts.
To be honest - I have used both methods extensively in the past and no longer bother using either. Table exists when running the table create script? So what. If the table should not exist, use server exceptions in SQL*Plus to cease processing and exit. If it does not matter whether the table exists or not, why be concern with running the script to create the table if the table already exists?