CODEWITHSUNDEEP
c#entity-frameworkentity-framework-coreef-core-3.1ef-core-3.0
Augusto Will
Augusto Will

Reputation: 592

How to reuse a function inside a where in EF Core?

I have a query that select all Photos if its public, and only if friends if visibility is private in this code.

_communityDbContext
            .Photos
            .Where(x => (
                    x.Privacy == 1 ||
                    (x.Privacy == 2 &&
                     _communityDbContext.Friendships.FirstOrDefault(d => x.CreatedBy.Id == user1 && d.FriendUser.Id == user2) !=
                     null)
                )
            );

But I trying to extract this piece of code to reuse in another queries

_communityDbContext.Friendships.FirstOrDefault(d => x.CreatedBy.Id == user1 && d.FriendUser.Id == user2) != null

Is possible to call an function and make the code like that:

_communityDbContext
            .Photos
            .Where(x => (
                    x.Privacy == 1 ||
                    (x.Privacy == 2 &&
                    hasFriendship(x.CreatedBy.Id, user))
                )
            );

Upvotes: 2

Views: 1566

Answers (1)

Augusto Will
Augusto Will

Reputation: 592

I fond a solution, the method invocation must be done to an expression, not to a function call. So I can extract that part of code by doing

public Expression<Func<Photo, bool>> Visible()
    {
        return x => (
            x.Privacy == 1 ||
            (x.Privacy == 2 &&
             _communityDbContext.Friendships.FirstOrDefault(d => x.CreatedBy.Id == 3 && d.FriendUser.Id == 3) !=
             null)
        );
    }

And calling this by

.where(Visible())

Upvotes: 2

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