generic repository doesn't let me add methods-CodePudding

I'm building an ASP.NET Core web application. The controller use a generic repository within methods like "Get, GetById, Post, Update ecc.". When i use these methods in the controller and I try to add methods like "Include, Where ecc." pops this error : CS1501 :

"No overload for method 'method' takes 'number' arguments"

var license = await _repo.GetSingleById(id).Include("product");

i tried to return also IQueryable but it gaves me the same error.

CodePudding user response：

I'm going to guess that:

_repo.GetSingleById(id)

looks something like:

public async Task<License> GetSingleById(int id)
    => dbContext.dbSetLicences.SingleOrDefaultAsync(item => item.Id == id);

If so then your _repo.GetSingleById(id).Include("product") is trying to apply Include to a Task and then you are awaiting the whole thing, which isn't going to work!

You need to do something like this:

public async ValueTask<License> GetSingleByIdAsync(int id)
    => dbContext.dbSetLicences.Include("product").SingleOrDefaultAsync(item => item.Id == id);

dbSetLicences.Include("product") doesn't generate an IEnumerable dataset which SingleorDefaultAsync gets applied to. It produces an IQueryable object that only gets executed when you call SingleorDefaultAsync. EF will figure out the most "economic" way to generate the real Db query.

This should also work though I haven't tested it.

public async ValueTask<License> GetSingleByIdAsync(int id, bool withProduct)
{
    var query = dbcontent.dbSetLicences;
    if(withProduct)
       query = query.Include("product")

     return query.SingleOrDefaultAsync(item => item.Id == id);
}

CodePudding user response：

The error is probably because the method Include requires arguments.

e.g.

var license = await _repo.GetSingleById(id).Include(l => l.ThingIWantToInclude);