Procedure call inside a PL/SQL block

Question

I have some SQL code to populate a database, which works just fine:

INSERT INTO PDF_DOCUMENT_ELEMENT (DOCUMENT_ELEMENT_ID, DOCUMENT_ID, ELEMENT_ID) VALUES (1, 1, 1);
INSERT INTO PDF_DOCUMENT_ELEMENT (DOCUMENT_ELEMENT_ID, DOCUMENT_ID, ELEMENT_ID) VALUES (2, 1, 1);
INSERT INTO PDF_DOCUMENT_ELEMENT (DOCUMENT_ELEMENT_ID, DOCUMENT_ID, ELEMENT_ID) VALUES (3, 1, 2);

EXECUTE RESET_SEQUENCE('DOCUMENT_ELEMENT_ID_SEQ', 4);

To enhance maintainability, I'm trying to replace some magic numbers with variables. I've never used variables before but I've read I need to use a PL/SQL block so:

DECLARE
    ELEMENT_TEXT SMALLINT := 1;
    ELEMENT_IMAGE SMALLINT := 2;
BEGIN

INSERT INTO PDF_DOCUMENT_ELEMENT (DOCUMENT_ELEMENT_ID, DOCUMENT_ID, ELEMENT_ID) VALUES (1, 1, ELEMENT_TEXT);
INSERT INTO PDF_DOCUMENT_ELEMENT (DOCUMENT_ELEMENT_ID, DOCUMENT_ID, ELEMENT_ID) VALUES (2, 1, ELEMENT_TEXT);
INSERT INTO PDF_DOCUMENT_ELEMENT (DOCUMENT_ELEMENT_ID, DOCUMENT_ID, ELEMENT_ID) VALUES (3, 1, ELEMENT_IMAGE);

EXECUTE RESET_SEQUENCE('DOCUMENT_ELEMENT_ID_SEQ', 4);

END;
/

This works just fine, except the procedure call:

EXECUTE RESET_SEQUENCE('DOCUMENT_ELEMENT_ID_SEQ', 4);
           *
ERROR en lÝnea 45:
ORA-06550: lÝnea 45, columna 9:
PLS-00103: Se ha encontrado el sÝmbolo "RESET_SEQUENCE" cuando se esperaba uno
de los siguientes:
:= . ( @ % ; immediate
El sÝmbolo ":=" ha sido sustituido por "RESET_SEQUENCE" para continuar.

The PLS-00103 error translates as:

PLS-00103: found 'string' but expected one of the following: 'string'

If I change the call to:

EXECUTE IMMEDIATE RESET_SEQUENCE('DOCUMENTO_ELEMENTO_ID_SEQ', 4);

... I get this:

PLS-00222: en este ßmbito no existe ninguna funci¾n cuyo nombre sea
'RESET_SEQUENCE'
ORA-06550: lÝnea 45, columna 1:
PL/SQL: Statement ignored

... that translates as:

PLS-00222: no function with name 'string' exists in this scope

My questions are:

1. Am I using variables correctly or there's a better solution for my initial goal?
2. What do I need to fix in my procedure call syntax and why?

Answer 1

1. IMO, it would be better if you had a procedure with 3 parameters, where you would have 1 insert...and then use that procedure to make the inserts. That way you can add exception handling, and if something happens you would know.

2. Try deleting the EXECUTE when using the block version of your code. I don't think you need it :)

Answer 2

A procedure call is not plain SQL, it's PL/SQL. As such, you need to run it from PL/SQL context. Options include:

• Create a PL/SQL block and invoke the procedure directly:

  BEGIN
      RESET_SEQUENCE('DOCUMENT_ELEMENT_ID_SEQ', 4);
  END;
  /
  

• If you are at SQL*Plus, you can use the EXECUTE internal command:

  EXECUTE RESET_SEQUENCE('DOCUMENT_ELEMENT_ID_SEQ', 4);
  

My problem was that I was issuing a SQL*Plus command inside a PL/SQL block.

(As of EXECUTE IMMEDIATE, it's a PL/SQL command to run a dynamically generated SQL statement or anonymous PL/SQL block. It expects a string and has nothing to do with this question. Oracle only suggested it because its name resembles the SQL*Plus command.)

Answer 3

If the initial goal is to avoid the use of magic numbers then the solution is to use a table with the meaning of those numbers and to reference that.

So ...

 create table element (
   element_id   integer primary key,
   element_name varchar2(30) not null unique);

 insert into element values (1,'Text');
 insert into element values (2,'Image');

 INSERT INTO PDF_DOCUMENT_ELEMENT (DOCUMENT_ELEMENT_ID, DOCUMENT_ID, ELEMENT_ID)
 Select 1, 1, element_id
 from   elements
 where  element_name = 'Text';

 INSERT INTO PDF_DOCUMENT_ELEMENT (DOCUMENT_ELEMENT_ID, DOCUMENT_ID, ELEMENT_ID)
 Select 1, 1, element_id
 from   elements
 where  element_name = 'Text';

 INSERT INTO PDF_DOCUMENT_ELEMENT (DOCUMENT_ELEMENT_ID, DOCUMENT_ID, ELEMENT_ID)
 Select 1, 1, element_id
 from   elements
 where  element_name = 'Image';