Parameter evaluation against harcoded string always return false In Mysql workbench I am trying to make query whit parameter.

But I have strange behavior when I try to compare parameter with static strings.

Why I do not get any rows form query like this ?
When I run query , I do get header rows, but I do not get any row.
I am sure that there is rows in table calls.
Forgive me if this too obvious but I in MsSql I did this million times without issues.

set @kontakt ='fo' ;
select
*
from calls
where (@kontakt = 'fo');
I tried it and it is working as expected:
http://sqlfiddle.com/#!9/b92cd1/1

However, some clients deals with every one statement as a single transaction. Try to add all of your code to one transaction and execute it.

I tested that in MySQL client (command line in Linux) and on SQL Fiddle (Link above)