[sql-server] How do I declare and use variables in PL/SQL like I do in T-SQL?

In Sql Server, often times when I'm testing the body of a stored procedure, I copy the body into SSMS, DECLARE the variables at the top of the page, set them to some sample values, and execute the body as-is.

For Example, if my proc is

CREATE PROC MySampleProc
    @Name   VARCHAR(20)
AS
    SELECT @Name

Then my test sql would be

DECLARE @Name VARCHAR(20)
SET     @Name = 'Tom'

    SELECT @Name

What is the Oracle PL/SQL equivalent to this?

This is the closest that I've come up with, but I'm getting "PLS-00428: an INTO clause is expected in this SELECT statement"

DECLARE
   myname varchar2(20);
BEGIN
     myname := 'Tom';

     select myname from DUAL;
END;

This is a better example of what I'm really trying to do:

DECLARE
   myname varchar2(20);
BEGIN
     myname := 'Tom';

     SELECT *
     FROM   Customers
     WHERE  Name = myname;
END;

But again, it wants an 'INTO' when really I just want the records printed on the screen, not stored in another table....

RESOLVED:

Thanks to @Allan, I've got it working well enough. Oracle SQL Developer apparently remembers the parameter values you supply it with. PL/SQL Developer, however, wants nothing to do with this....

If you "Run As Script", it will abide by your defaults, but it will only return results as ASCI text, not in a grid/spreadsheet

Variables are not defined, but declared.

This is possible duplicate of declare variables in a pl/sql block

But you can look here :

http://docs.oracle.com/cd/B19306_01/appdev.102/b14261/fundamentals.htm#i27306

http://docs.oracle.com/cd/B19306_01/appdev.102/b14261/overview.htm

UPDATE:

Refer here : How to return a resultset / cursor from a Oracle PL/SQL anonymous block that executes Dynamic SQL?

In Oracle PL/SQL, if you are running a query that may return multiple rows, you need a cursor to iterate over the results. The simplest way is with a for loop, e.g.:

declare
  myname varchar2(20) := 'tom';
begin
  for result_cursor in (select * from mytable where first_name = myname) loop
    dbms_output.put_line(result_cursor.first_name);
    dbms_output.put_line(result_cursor.other_field);
  end loop;
end;

If you have a query that returns exactly one row, then you can use the select...into... syntax, e.g.:

declare 
  myname varchar2(20);
begin
  select first_name into myname 
    from mytable 
    where person_id = 123;
end;