Question

I have a many-to-many relationship in my code and I am trying to seed the database. Here is my seed method:

var loc = new List<Location> {
      new Location { LocationName = "Paradise Lane" },
      new Location { LocationName = "81st Street" }
};
loc.ForEach(l => context.Locations.Add(l));


var soft = new List<Software> {
     new Software { Title = "Adobe Creative Suite", ... Locations = loc.Single(s => s.LocationName = "Paradise Lane")}
};
soft.ForEach(s => context.Software.Add(s));

Here is my locations class:

public class Location
    {
        public int Id { get; set; }
        [Required]
        [StringLength(20)]
        public string LocationName { get; set; }
        public virtual ICollection<Software> Software { get; set; }
    }

Here is my software class:

public class Software
    {
        public int Id { get; set; }
        [Required]
        [StringLength(128)]
        public string Title { get; set; }
        [Required]
        [StringLength(10)]
        public string Version { get; set; }
        [Required]
        [StringLength(128)]
        public string SerialNumber { get; set; }
        [Required]
        [StringLength(3)]
        public string Platform { get; set; }
        [StringLength(1000)]
        public string Notes { get; set; }
        [Required]
        [StringLength(15)]
        public string PurchaseDate { get; set; }
        public bool Suite { get; set; }
        public string SubscriptionEndDate { get; set; }
        //[Required]
        //[StringLength(3)]
        public int SeatCount { get; set; }
        public virtual ICollection<Location> Locations { get; set; }
        public virtual ICollection<SoftwarePublisher> Publishers { get; set; }
        public virtual ICollection<SoftwareType> Types { get; set; }

    }

I am getting two errors. One, it tells me I cannot implicitly convert string to bool. I didn’t even know I was trying to do t hat. And two, cannot convert lambda express to delegate because soem fo the return types in the block are not implicitly convertable to the delegate return type. Is that a reference to the iCollection?

Answer 1

You missed an equals sign. Double equals for comparing.

loc.Single(s => s.LocationName = "Paradise Lane")

vs

loc.Single(s => s.LocationName == "Paradise Lane")

Also, you can’t do a .Single() into Locations because it is an ICollection. Single returns 1 object, not a collection. You should use .Where instead. Or you can implicitly declare an array in there and use your .Single() code inside it.

Edit: Also apparently .Where() doesn’t cast nicely to ICollection. Add a ToArray and you’ll get an array which is acceptable.