Re: What is PL/SQL?

Hi Michael,

>What is PL/SQL?

PL stands for procedure language. It is the 3rd GL for Oracle. It allows you to do more with the data than with standard 4GL. For instance, you can operate on each row, use procedures, functions and cursors.

>How does it relate to regular SQL?

It's an extension from Oracle and is only supported by Oracle.

>Will knowledge of regular SQL be of any use when using PL/SQL?

Sure! You still have to write queries to retrieve your data, but you can do more. Suppose you want to retrieve all names of the employees. Of course, the following query will do:

select surname from employees;

But watch what you can do with PL/SQL:

declare
  cursor c_emp is select deptno, surname from employees; begin
  for r_emp in c_emp loop
    if deptno = 10 then
      insert into great_department (surname) values (r_emp.surname);     elsif deptno = 20 then
      insert into losers_department (surname) values (r_emp.surname);     end if;
  end loop;
  commit;
exception
  when others then
    rollback;
end;

>Is there a spec online?

Try www.oracle.com and try the search engine.

>Is it an oracle specific technology?

Yep.

>If so, what versions of Oracle support PL/SQL?

A database with the procedure language support. It's very common to install the PL/SQL feature.

>Are there different versions of PL/SQL?

I do believe so.

• Martin Jesterhoudt
• Martin.Jesterhoudt(replace this by @)usa.net

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