How to declare variables in a simple sql query?

Question

Oracle

Hello query: insert into MY_TABLE_TAB ( Col1
, Col2, Col3) Values ​​(:Param1, :Param2, :Param3)
something like this:
param1 = 123
param2 = 234
param3 = 345
We are talking about the execution in Oracle SQL Developer, not PL/SQL,

Answer 1

DECLARE
   param1 NUMBER := 123;
   param2 NUMBER := 234;
   param3 NUMBER := 345;
BEGIN
     insert into MY_TABLE_TAB (Col1, Col2, Col3) Values (:param1, :param2, :param3)
END;

Answer 2

It is necessary to speak about variables in the context of the development environment in which you plan to execute the request. If we talk about SQLPlus, then something like this (slammed from SQL.ru):

SET DEFINE "&"
VAR db_name VARCHAR2(30)
COLUMN db_name NEW_VALUE db_name
EXEC :db_name := 'Blah';
SELECT :db_name AS db_name FROM dual;
DEFINE db_name