Declare variable syntax invalid in MySQL Workbench?

Question

I am trying to create and set a variable:

DECLARE myId INT;
SET myId = 5;

However, I am getting invalid syntax complaint in MySQL Workbench:

SQL syntax error near 'DECLARE myId INT;'

I have tried the following variants:

DECLARE myId INT(4);
SET myId = 5;

DECLARE @myId INT;
SET @myId = 5;

DECLARE @myId INT(4);
SET @myId = 5;

What is wrong?

Answer 1

Try

SET @myId := 100;

Then if you do

select @myId;

You will get 100