sql server - A SELECT statement that assigns a value to a variable must not be combined with data-retrieval operations1 -

i keep getting error

a select statement assigns value variable must not combined data-retrieval operations

when run code:

select      @i = users,     (name + ' ' + surname) names        dbo.helpdeskusers       [names] @userid  

i tried way ...

set    @i = (select               [users],             ([name] + ' ' + [surname]) [names]                       dbo.helpdeskusers                       names @userid)  

and error:

msg 207, level 16, state 1, procedure test, line 17
invalid column name 'names'

msg 116, level 16, state 1, procedure test, line 19
1 expression can specified in select list when subquery not introduced exists.

you cannot use alias name in same select query where clause , have many other mistakes in query

if not wrong looking this

select @i=users  dbo.helpdeskusers  name + ' ' + surname  = @userid 

this how query logically processed

1. 2. on 3. outer 4. 5. group 6. cube | rollup 7. having 8. select 9. distinct 10 order 11. top 

as can see select comes after where clause cannot use alias name in where generated in select