CODEWITHSUNDEEP
c#asp.net-mvcentity-frameworklinqasp.net-mvc-4
Lasha Amashukeli
Lasha Amashukeli

Reputation: 83

Using Math functions in Entity framework with mysql

I am developing ASP.NET MVC application and use Mysql with entity framework in it. But I'm having trouble with executing Linq query like this:

var place= dbContext.Places.FirstOrDefault(x => Math.Sqrt(x.Lat) > 0);

I also tried using SqlFunctions:

var place= dbContext.Places.FirstOrDefault(x => SqlFunctions.SquareRoot(x.Lat) > 0);

But either way I'm getting 'System.NotSupportedException':

Additional information: The specified method 'System.Nullable1[System.Double] SquareRoot(System.Nullable1[System.Decimal])' on the type 'System.Data.Entity.SqlServer.SqlFunctions' cannot be translated into a LINQ to Entities store expression.

Is there any way to use Square root function so that it could be translated into a LINQ to Entities expression?

Upvotes: 5

Views: 2310

Answers (2)

freshbm
freshbm

Reputation: 5632

Entity Framework doesn't support Sqrt function:

Math Canonical Functions - list of supported functions.

So you can use Math.Pow insted:

var place= dbContext.Places.FirstOrDefault(x => Math.Pow(x.Lat,0.5) > 0);

Upvotes: 9

Ant
Ant

Reputation: 338

Here you are trying to perform math.sqrt against the sql database which is not supported.

You would need to either use SQLFunctions or perform a ToList() after dbContext.Places. However, depending on how many places you bring back this would be inefficient.

var place= dbContext.Places.ToList().FirstOrDefault(x => Math.Sqrt(x.Lat) > 0);

Upvotes: 0

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