Because the query is simply an Expression that gets translated into SQL.

EF doens't know how to translate Int32.Parse into an equivalent SQL statement, so it fails.

why EF cant translate Int32.Pars(...?
Quite a few phrases in English are constructed like so:


  How [adjective] a [noun]...?


This is the question form of the construction, which is often answered with the negative:


  Not that [adjective] a [noun].


or the positive:


  Quite [adjective] a [noun].


However, from time to time I'll hear the word 'of' inserted before the 'a', e.g.:


  Not that [adjective] of a [noun].


This usually sounds wrong to me, with the exception of the case where the adjective 'much' is used.  So, this sounds fine to my ear:


  Not that much of a problem.


whereas this doesn't:


  Not that loud of a noise.


Why is it that 'much' should be used with 'of', and other adjectives not?  Is it because 'much' is seen as measuring a quantity (of something), whereas other adjectives that may be used in this construction are seen as measuring the quality of a whole thing?
