在多对多关系中添加where子句

Question

I want to build a directory for restaurant, the search is based in three condition the problem that I have is add the third where clause that uses typecuisine like you see in code the 2 first conditions are good my entity

var query = db.Restaurants.AsQueryable();

if (!string.IsNullOrEmpty(Name))
    query = query.Where(c => c.Nom.Contains(Name));

if (RegionId != Guid.Empty)
    query = query.Where(c => c.RegionId == RegionId);

//how to get typecuisine ID from table Restaurant instead it's only in  table TypeCuisine


if (typeId != Guid.Empty)
    query = query.Where(tc=> tc.TypeCuisines.Where(r=>r.TypeCuisineId == typeId));

return query.ToList();

Answer 1

The .Where is expecting a return type of bool and you are returning the results of an inner Where , meaning an IEnumerable .

What you are missing is the .Any() function instead of the inner Where .

var query = db.Restaurants.AsQueryable();

if (!string.IsNullOrEmpty(Name))
    query = query.Where(c => c.Nom.Contains(Name));

if (RegionId != Guid.Empty)
    query = query.Where(c => c.RegionId == RegionId);

if (typeId != Guid.Empty)
    query = query.Where(tc=> tc.TypeCuisines.Any(r => r.TypeCuisineId == typeId));

return query.ToList();