Delete a single record from Entity Framework

Question

I have a SQL Server table in Entity Framework named employ with a single key column named ID   How do I delete a single record from the table using Entity Framework

User · Answer

Employer employer   context Employers First x   gt  x EmployerId    1    context Customers DeleteObject employer   context SaveChanges

User · Answer

u can do it simply like this      public ActionResult Delete int  id                using  var db   new RegistrationEntities                          Models RegisterTable Obj   new Models RegisterTable                Registration DAL RegisterDbTable personalDetail   db RegisterDbTable Find id               if  personalDetail    null                                return HttpNotFound                              else                               Obj UserID   personalDetail UserID                  Obj FirstName   personalDetail FName                  Obj LastName   personalDetail LName                  Obj City   personalDetail City                             return View Obj                          HttpPost  ActionName  Delete         public ActionResult DeleteConfirmed int  id                using  var db   new RegistrationEntities                          Registration DAL RegisterDbTable personalDetail   db RegisterDbTable Find id               db RegisterDbTable Remove personalDetail               db SaveChanges                return RedirectToAction  where u want it to redirect                      model   public class RegisterTable        public int UserID       get  set          public string FirstName       get  set          public string LastName       get  set          public string Password       get  set          public string City       get  set          view from which u will call it     lt table class  table  gt       lt tr gt           lt th gt              FirstName          lt  th gt           lt th gt              LastName          lt  th gt            lt th gt              City          lt  th gt           lt th gt  lt  th gt       lt  tr gt        foreach  var item in Model                 lt tr gt               lt td gt   item FirstName  lt  td gt               lt td gt   item LastName  lt  td gt               lt td gt   item City lt  td gt               lt td gt                   lt a href   Url Action  Edit    Registeration   new   id   item UserID     gt Edit lt  a gt                     lt a href   Url Action  Details    Registeration   new   id   item UserID     gt Details lt  a gt                     lt a href   Url Action  Delete    Registeration   new   id   item UserID     gt Delete lt  a gt                lt  td gt           lt  tr gt           lt  table gt    i hope this will be easy for u to understand

User · Answer

The best way is to check and then delete          if  ctx Employ Any r  gt r Id    entity Id                         Employ rec   new Employ     Id   entity Id                ctx Entry rec  State   EntityState Deleted              ctx SaveChanges

User · Answer

For a generic DAO this worked      public void Delete T entity                db Entry entity  State   EntityState Deleted          db SaveChanges

User · Answer

You can do something like this in your click or celldoubleclick event of your grid if you used one   if dgEmp CurrentRow Index    -1         employ Id    Int32 dgEmp CurrentRow Cells  Id   Value        Some other stuff here      Then do something like this in your Delete Button   using Context context   new Context           var entry   context Entry employ        if entry State    EntityState Detached                   Attached it since the record is already being tracked         context Employee Attach employ                                              Use Remove method to remove it virtually from the memory                     context Employee Remove employ          Finally  execute SaveChanges method to finalized the delete command         to the actual table      context SaveChanges            Some stuff here     Alternatively  you can use a LINQ Query instead of using LINQ To Entities Query   var query    from emp in db Employee where emp Id    employ Id select emp  Single      employ Id is used as filtering parameter which was already passed from the CellDoubleClick Event of your DataGridView

User · Answer

HttpPost      public JsonResult DeleteCotnact int id                using  MycasedbEntities dbde   new MycasedbEntities                          Contact rowcontact    from c in dbde Contact                                      where c Id    id                                      select c  FirstOrDefault                 dbde Contact Remove rowcontact               dbde SaveChanges                 return Json id                     What do you think of this  simple or not  you could also try this           var productrow   cnn Product Find id           cnn Product Remove productrow           cnn SaveChanges

User · Answer

You can use SingleOrDefault to get a single object matching your criteria  and then pass that to the Remove method of your EF table   var itemToRemove   Context Employ SingleOrDefault x   gt  x id    1     returns a single item   if  itemToRemove    null        Context Employ Remove itemToRemove       Context SaveChanges

User · Answer

I am using entity framework with LINQ  Following code was helpful for me   1- For multiple records   using  var dbContext   new Chat ServerEntities            var allRec  dbContext myEntities       dbContext myEntities RemoveRange allRec        dbContext SaveChanges         2- For Single record   using  var dbContext   new Chat ServerEntities            var singleRec   dbContext ChatUserConnections FirstOrDefault  x   gt  x ID   1     object your want to delete      dbContext ChatUserConnections Remove singleRec        dbContext SaveChanges

User · Answer

More generic approuch  public virtual void Delete lt T gt  int id  where T   BaseEntity  new         T instance   Activator CreateInstance lt T gt         instance Id   id      if  dbContext Entry lt T gt  entity  State    EntityState Detached                dbContext Set lt T gt    Attach entity              dbContext Set lt T gt    Remove entity

User · Answer

Just wanted to contribute the three methods I ve bounced back and forth with   Method 1   var record   ctx Records FirstOrDefault    ctx Records Remove record   ctx SaveChanges      Method 2   var record   ctx Records FirstOfDefault    ctx Entry record  State   EntityState Deleted  ctx SaveChanges    ctx Entry record  State   EntityState Detached    One of the reasons why I prefer to go with Method 2 is because in the case of setting EF or EFCore to QueryTrackingBehavior NoTracking  it s safer to do   Then there s Method 3   var record   ctx Records FirstOrDefault    var entry   ctx Entry record   record DeletedOn   DateTimeOffset Now  entry State   EntityState Modified  ctx SaveChanges    entry State   EntityState Detached    This utilizes a soft delete approach by setting the record s DeletedOn property  and still being able to keep the record for future use  what ever that may be  Basically  putting it in the Recycle Bin     Also  in regards to Method 3  instead of setting the entire record to being modified   entry State   EntityState Modified    You would also simply set only the column DeletedOn as modified   entry Property x   gt  x DeletedOn  IsModified   true

User · Answer

var stud    from s1 in entities Students             where s1 ID   student ID             select s1  SingleOrDefault         Delete it from memory   entities DeleteObject stud       Save to database   entities SaveChanges

User · Answer

With Entity Framework 6  you can use Remove  Also it  s a good tactic to use using for being sure that your connection is closed   using  var context   new EmployDbContext          Employ emp   context Employ Where x   gt  x Id    id  Single lt Employ gt         context Employ Remove emp       context SaveChanges

User · Answer

It s not necessary to query the object first  you can attach it to the context by its id  Like this   var employer   new Employ   Id   1    ctx Employ Attach employer   ctx Employ Remove employer   ctx SaveChanges      Alternatively  you can set the attached entry s state to deleted    var employer   new Employ   Id   1    ctx Entry employer  State   EntityState Deleted  ctx SaveChanges

User · Answer

Using EntityFramework Plus could be an option   dbContext Employ Where e   gt  e Id    1  Delete      More examples are available here

User · Answer

Here s a safe way   using  var transitron   ctx Database BeginTransaction        try         var employer   new Employ   Id   1        ctx Entry employer  State   EntityState Deleted      ctx SaveChanges        transitron Commit          catch  Exception ex          transitron Rollback          capture exception like  entity does not exist  Id property does not exist  etc            Here you can pile up all the changes you want  so you can do a series of deletion before the SaveChanges and Commit  so they will be applied only if they are all successful

[c#] Delete a single record from Entity Framework?

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