In Linq, is a SELECT required when WHERE is used?

Question

If you have a Linq statement that uses a WHERE clause, for example:

var result = someCollection.Where(x => x.value > 5).Select(x => x);

Is the SELECT required, or is it redundant? It appears that I can safely omit the SELECT if I'm not trying to get at an object property, but am not sure if this is proper...

Select is redundant you can remove it. – kosmo16 Jul 08 '15 at 17:49 — kosmo16, Jul 08 '15 at 17:49

score 4 · Accepted Answer · answered Jul 08 '15 at 17:46

4

In your case No, it is not required, since you are selecting the object. So you can have:

var result = someCollection.Where(x => x.value > 5);

as far as better practice is concerned, I would remove the redundant code.

But, if you are going to select a specific property then that could be useful, like:

var result = someCollection.Where(x => x.value > 5)
                   .Select(x=> x.SomeSpecificProperty);

One more thing to add, with query expression you will need the select.

var result = from x in someCollection
             where x.Value > 5
             select x;

but at compile time the above query expression will be converted to Method Expression, without Select.

answered Jul 08 '15 at 17:46

Habib

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Ah, I think that was where my confusion came from... that there is a difference between query and lambda syntax. Thanks. – newmanth Jul 08 '15 at 17:51
@newmanth, yes there is *only* the difference in syntax, otherwise query expression compiles into method expression. You can read more about it [here](http://stackoverflow.com/questions/15677958/difference-between-query-expression-and-method-expression-in-linq) – Habib Jul 08 '15 at 17:53

score 0 · Answer 2 · answered Jul 08 '15 at 17:47

0

It's redundant. Select is more like the functional map (see JavaScript, Haskell, Ruby). If you aren't going to transform the input object into a different form than it is currently in, there's no need to use Select.

answered Jul 08 '15 at 17:47

Dan

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score 0 · Answer 3 · answered Jul 08 '15 at 17:47

0

In Linq, is a SELECT required when WHERE is used?

No, it isnt.

answered Jul 08 '15 at 17:47

maraaaaaaaa

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score 0 · Answer 4 · answered Jul 08 '15 at 17:47

No... is not necessary this time... may be if you want to select a new object different than "someCollection" it will be necessary

something like:

var result = someCollection.Where(x => x.value > 5).Select(x => new ObjName() { name = x.name, lastname = x.lastname });

In Linq, is a SELECT required when WHERE is used?

4 Answers4