Linq query to select any in list against a list-CodePudding

Using EF Core code-first, and I want to find any record with a similar list of a foreign entities to the entity I already have.

public class ClownModel {
    public int Id { get; set; }
    public List<CarModel> Cars { get; set; }
}
public class CarModel {
    public int Id { get; set; }
}

var MyClown = new ClownModel() { /*add properties*/ } 
//or maybe an existing record selected from database, just some ClownModel instance

Basically, "Select all the ClownModels where they have any Cars.Id that are in my MyClown.Cars"

CodePudding user response：

Assuming that ClownModel has unique CarModel Id's, you can use the following query:

Matches All Ids

var ids = MyClown.Cars.Select(c => c.Id).ToList();

var query = 
    from cm in ctx.ClownModel
    where cm.Cars.Where(c => ids.Contains(c.Id)).Count() == ids.Count
    select cm;

Matches Any Ids

var ids = MyClown.Cars.Select(c => c.Id).ToList();

var query = 
    from cm in ctx.ClownModel
    where cm.Cars.Where(c => ids.Contains(c.Id)).Any()
    select cm;