Question

I have a table set up like so:

prefix | value
 ABC     1234
 ABC     5678
 DEF     1234

Is it possible to create a linq query where prefix and value are concatenated for comparison in the where clause? I’ve tried this, but it always returns an empty set:

selected =
            from i in dc.items
            where i.prefix + i.value == "ABC1234"
            select i;

Edit: the following T-SQL comes up with the correct results:

 WHERE LTRIM(RTRIM([prefix])) + LTRIM(RTRIM([value])) = 'ABC1234'

Edit2: The following, which combines most of the answers below, still does not work:

where (String.Concat(i.prefix.Trim(), i.value.Trim())) == "ABC1234"

Edit3: So I’ve got it working, but I have no clue why. I’ve accepted an answer but if someone posts why it works I’d be grateful 🙂

This works (returns n rows):

var temp = dc.items.Where(i => i.prefix.Trim() + i.prefix.Trim() == "ABC1234");

This does not work (returns 0 rows):

var temp =
            from i in dc.items
            where i.prefix.Trim() + i.value.Trim() == "ABC1234"
            select i;

Answer 1

I dont’s speak english. Try this:

var selected = dc.Where(x => x.prefix + x.value == "ABC1234");