What is the simplest way to define a local variable in Oracle?

Question

In the SQL Server, I can define local variables like this.

declare @id number := 1000

select * from tbl_A where id = @id;
select * from tbl_B where id = @id         


        

Answer 1

(Just stumbled across this thread.) Beginning with SQL*Plus 12.2, you can declare and assign a value at the same time:

SQL> var id number = 1000

SQL> select * from tbl_A where id = :id;

Oracle calls it input binding.

If you must do it in PL/SQL, the answer was given by others.