CODEWITHSUNDEEP
c#.netlinq
user786
user786

Reputation: 4364

Linq check for percentage in where clause

I am trying to check some percent of value in where clause in Linq

following is my code

  List<string> v = await context.Categories.Where(w =>(w.id / 2) * 100 == 50)
                             .Select(w => w.id.ToString()).ToListAsync();

the problem is there is record that meets the condition but no record is selecting. I tried using Convert.ToDecimal(w.id/2) but its not working either.

How can I get the percent checking in where clause? and why the above code not working?

Upvotes: 1

Views: 173

Answers (3)

Mick
Mick

Reputation: 6864

How about changing the order of operations....

List<string> v = await context.Categories.Where(w => 100 * w.id / 2 == 50)
                             .Select(w => w.id.ToString()).ToListAsync();

or

List<string> v = await context.Categories.Where(w => 50 * w.id == 50)
                             .Select(w => w.id.ToString()).ToListAsync();

or

List<string> v = await context.Categories.Where(w => w.id == 1)
                             .Select(w => w.id.ToString()).ToListAsync();

Upvotes: 3

Daniel
Daniel

Reputation: 2804

If id is an integer it does supportswhole numbers so 1/2 = 0. You need to force a cast to a double (a type that supports decimal places) before you operate on it.

 List<string> v = await context.Categories.Where(w =>(w.id / 2.0) * 100 == 50)
                             .Select(w => w.id.ToString()).ToListAsync();

Upvotes: 2

Alex
Alex

Reputation: 23300

Unless I'm missing something, you don't seem to need the calculation:

w =>(w.id / 2) * 100 == 50

can be written as

w => w.id == 1

Upvotes: 2

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