Question

My goal is to make a deletion function that uses LINQ to delete a record from a database table by finding the id the user inputs that matches the record’s primary key.

• MyDBEntitiesClass is the argument that the function needs to be passed which tells it what DataTable to search.

• IDontKnowWhatType is the type I’m asking for help in determining.

• MyPrimaryKey needs to be replaced with something that references the primary key of MyDBEntitiesClass.

• TestDatabaseEntities is the name of the connection string created by generating an entity model from my existing SQL server database.

public static void DeleteFrom(IDontKnowWhatType MyDBEntitiesClass)
{

var dbEntities = new TestDatabaseEntities(); 

    //Prompt the user for an ID
    Console.WriteLine("Select ID for deletion.");

    // save the ID to IDtoMark
    int IDtoMark = int.Parse(Console.ReadLine());
    try
    {
        // return a single record that matches IDtoMark 
        MyDbEntitiesClass x = dbEntities.MyDbEntitiesClass.Single(x => x.myPrimaryKey == IDtoMark);
        //Remove the marked record, and save changes
        dbEntities.MyDbEntitiesClass.Remove(x);
        dbEntities.SaveChanges();
    }
    catch(Exception ex)
    {
        Console.WriteLine(ex.Message);
    }
}

Answer 1

You can achieve this by implementing Repository Pattern.

I guess you are using entity framework. For that you have generic class.

public class Repository<T> where T : class
{
    private DbContext dbContext;
    private DbSet<T> DbSet { get; set }
    public Repository(dbContext)
    {
       this.dbContext = dbContext;
       this.DbSet = this.dbContext.DbSet<T>();
    }

    public void Delete(int id)
    {
         T entity = DbSet.Find(id);
         DbSet.Remove(entity);
         dbContext.Save();
    }

}