How do I use variables in Oracle SQL Developer?

Question

I am using the SQL-Developer in Version 3.2. The other stuff didn't work for me, but this did:

define value1 = 'sysdate'

SELECT &&value1 from dual;

Also it's the slickest way presented here, yet.

(If you omit the "define"-part you'll be prompted for that value)

There are two types of variable in SQL-plus: substitution and bind.

This is substitution (substitution variables can replace SQL*Plus command options or other hard-coded text):

define a = 1;
select &a from dual;
undefine a;

This is bind (bind variables store data values for SQL and PL/SQL statements executed in the RDBMS; they can hold single values or complete result sets):

var x number;
exec :x := 10;
select :x from dual;
exec select count(*) into :x from dual;
exec print x;

SQL Developer supports substitution variables, but when you execute a query with bind :var syntax you are prompted for the binding (in a dialog box).

Reference:

• http://www.oracle.com/technetwork/testcontent/sub-var-087723.html SQL*Plus Substitution Variables, Christopher Jones, 2004

UPDATE substitution variables are a bit tricky to use, look:

define phone = '+38097666666';
select &phone from dual; -- plus is stripped as it is a number
select '&phone' from dual; -- plus is preserved as it is a string

In SQL*Plus, you can do something very similar

SQL> variable v_emp_id number;
SQL> select 1234 into :v_emp_id from dual;

      1234
----------
      1234

SQL> select *
  2    from emp
  3   where empno = :v_emp_id;

no rows selected

In SQL Developer, if you run a statement that has any number of bind variables (prefixed with a colon), you'll be prompted to enter values. As Alex points out, you can also do something similar using the "Run Script" function (F5) with the alternate EXEC syntax Alex suggests does.

variable v_count number;
variable v_emp_id number;
exec :v_emp_id := 1234;
exec select count(1) into :v_count from emp;
select *
  from emp
 where empno = :v_emp_id
exec print :v_count;

Ok I know this a bit of a hack but this is a way to use a variable in a simple query, not a script:

WITH
    emplVar AS
    (SELECT 1234 AS id FROM dual)
SELECT
    *
FROM
    employees,
    emplVar
WHERE
    EmployId=emplVar.id;

You get to run it everywhere.

Simple answer NO.

However you can achieve something similar by running the following version using bind variables:

SELECT * FROM Employees WHERE EmployeeID = :EmpIDVar 

Once you run the query above in SQL Developer you will be prompted to enter value for the bind variable EmployeeID.

You can read up elsewhere on substitution variables; they're quite handy in SQL Developer. But I have fits trying to use bind variables in SQL Developer. This is what I do:

SET SERVEROUTPUT ON
declare
  v_testnum number;
  v_teststring varchar2(1000);

begin
   v_testnum := 2;
   DBMS_OUTPUT.put_line('v_testnum is now ' || v_testnum);

   SELECT 36,'hello world'
   INTO v_testnum, v_teststring
   from dual;

   DBMS_OUTPUT.put_line('v_testnum is now ' || v_testnum);
   DBMS_OUTPUT.put_line('v_teststring is ' || v_teststring);
end;

SET SERVEROUTPUT ON makes it so text can be printed to the script output console.

I believe what we're doing here is officially called PL/SQL. We have left the pure SQL land and are using a different engine in Oracle. You see the SELECT above? In PL/SQL you always have to SELECT ... INTO either variable or a refcursor. You can't just SELECT and return a result set in PL/SQL.

I think that the Easiest way in your case is :

DEFINE EmpIDVar = 1234;

SELECT *
FROM Employees
WHERE EmployeeID = &EmpIDVar

For the string values it will be like :

DEFINE EmpIDVar = '1234';

SELECT *
FROM Employees
WHERE EmployeeID = '&EmpIDVar'