I have simple database. Let i add using AddBookName record in table NamesSet database should generate random BookNameID. The main question is how to figure out the BookNameID that was generated to establish a connection to table Books?
Books:
CREATE TABLE [dbo].[BooksSet] (
[Id] INT IDENTITY (1, 1) NOT NULL,
[BookNameID] NVARCHAR (MAX) NOT NULL,
[PlaceID] NVARCHAR (MAX) NOT NULL,
CONSTRAINT [PK_BooksSet] PRIMARY KEY CLUSTERED ([Id] ASC)
);
Names
CREATE TABLE [dbo].[NamesSet] (
[BookNameID] INT IDENTITY (1, 1) NOT NULL,
[BookName] NVARCHAR (MAX) NOT NULL,
[Language] NVARCHAR (MAX) NOT NULL,
CONSTRAINT [PK_NamesSet] PRIMARY KEY CLUSTERED ([BookNameID] ASC)
);
HomeController:
public class HomeController : Controller
{
//
// GET: /Home/
TestEntities TE = new TestEntities();
public ActionResult Index()
{
return View();
}
[HttpPost]
public ActionResult AddBookName(Names name)
{
TE.NamesSet.Add(name);
TE.SaveChanges();
return View();
}
}
View:
#model TestDataBase.Models.Names
#{
ViewBag.Title = "Index";
}
<h2>Index</h2>
#using(#Html.BeginForm("AddBookName","Home"))
{
#Html.EditorFor(x=>x.BookName)
#Html.EditorFor(x => x.Language)
<input type="submit" value="Add name"/>
}
When you call SaveChanges(), any objects added to the context will be populated with the generated values from the database. So the generated value should be available after that line, in:
name.BookNameID
Related
I building simple project just for self-study and i have a little problem.
Im using Visual Studio and Entity Framework.
I builded a ASP.NET MVC 5 app where are CRUD functionality.
In database is connection between 2 tables like on
screenshot
HTTP POST bellow from CarController
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Save(Car car)
{
if (!ModelState.IsValid)
{
var viewModel = new CarFormViewModel()
{
Cars = car,
CarTypeModels = _context.CarTypeModels.ToList()
};
return View("CarForm", viewModel);
}
if (car.Id == 0)
_context.Cars.Add(car);
else
{
var customerInDb = _context.Cars.Single(c => c.Id == car.Id);
customerInDb.Name = car.Name;
customerInDb.HorsePower = car.HorsePower;
customerInDb.LinkToImage = car.LinkToImage;
customerInDb.CarTypeModelId = car.CarTypeModelId;
}
_context.SaveChanges();
return RedirectToAction("Index", "Car");
}
Im getting an error error
Db.CarTypeModel ->
CREATE TABLE [dbo].[CarTypeModels] (
[Id] TINYINT NOT NULL,
[Name] NVARCHAR (MAX) NULL,
CONSTRAINT [PK_dbo.CarTypeModels] PRIMARY KEY CLUSTERED ([Id] ASC));
db.Car ->
CREATE TABLE [dbo].[Cars] (
[Id] INT IDENTITY (1, 1) NOT NULL,
[Name] NVARCHAR (255) NULL,
[HorsePower] INT NOT NULL,
[LinkToImage] NVARCHAR (MAX) NULL,
[CarTypeModelId] TINYINT DEFAULT ((0)) NOT NULL,
CONSTRAINT [PK_dbo.Cars] PRIMARY KEY CLUSTERED ([Id] ASC),
CONSTRAINT [FK_dbo.Cars_dbo.CarTypeModels_CarTypeModelId] FOREIGN KEY ([CarTypeModelId]) REFERENCES [dbo].[CarTypeModels] ([Id]) ON DELETE CASCADE); GO CREATE NONCLUSTERED INDEX [IX_CarTypeModelId] ON [dbo].[Cars]([CarTypeModelId] ASC);
And code from CarForm which using CarTypeModelId
<div class="form-group">
#Html.LabelFor(m => m.Cars.CarTypeModelId)
#Html.DropDownListFor(m => m.Cars.CarTypeModelId, new SelectList(Model.CarTypeModels, "ID", "Name"), "Select car type", new { #class = "form-control" })
#Html.ValidationMessageFor(m => m.Cars.CarTypeModelId)
</div>
I have API Connection and its working fine. I think a problem is in CarController but I really dont know where...
//POST /api/cars
[HttpPost]
public IHttpActionResult CreateCar(CarDto carDto)
{
if (!ModelState.IsValid)
{
return BadRequest();
}
var car = Mapper.Map<CarDto, Car>(carDto);
_context.Cars.Add(car);
_context.SaveChanges();
carDto.Id = car.Id;
return Created(new Uri(Request.RequestUri + "/" + car.Id), carDto);
}
I think your dropdown list selection doesnt work properly and returns car.CarTypeModelId= 0. Try to fix the dropdown list by replacing "ID" by "Id" :
#Html.DropDownListFor(m => m.Cars.CarTypeModelId, new SelectList(Model.CarTypeModels, "Id", "Name"), "Select car type", new { #class = "form-control" })
I'm using MVC 5 with EF6 and Database first..
I have two tables, table A and B, both of them with non nullable fields.
I did the same procedure for both of them, create the controller and the view, but for some reason, the html of the view to create records for table B does not generate the client validations.
Table A:
CREATE TABLE [dbo].[A](
[ID] [int] IDENTITY(1,1) NOT NULL,
[CodA] [int] NOT NULL,
[Volume] [decimal](15, 2) NOT NULL,
[CreationDate] [datetime] NOT NULL,
CONSTRAINT [A_pk] PRIMARY KEY CLUSTERED
(
[ID] ASC
)
Table B:
CREATE TABLE [dbo].[B](
[ID] [smallint] IDENTITY(1,1) NOT NULL,
[Codigo] [varchar](3) NOT NULL,
[Iso2] [varchar](2) NOT NULL,
[Iso3] [varchar](3) NOT NULL,
[Designation] [nvarchar](128) NOT NULL,
CONSTRAINT [B_pk] PRIMARY KEY CLUSTERED
(
[ID] ASC
)
Html for a field in a view to create a record in table A:
<input class="form-control text-box single-line" data-val="true" data-val-number="The field Volume must be a number." data-val-required="The Volume field is required." id="Volume" name="Volume" type="text" value="">
Code from the cshtml create file for table A:
#Html.EditorFor(model => model.Volume, new { htmlAttributes = new { #class = "form-control" } })
Html for a field in a view to create a record in table B:
<input class="form-control text-box single-line" id="Codigo" name="Codigo" type="text" value="">
Code from the cshtml create file for table B:
#Html.EditorFor(model => model.Iso3, new { htmlAttributes = new { #class = "form-control" } })
Controller for the create action for table A
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create(A a)
{
if(ModelState.IsValid)
{
db.A.Add(a);
db.SaveChanges();
return RedirectToAction("Index", "Backoffice");
}
return View(a);
}
Controller for the create action for table B
[HttpPost]
[ValidateAntiForgeryToken]
public ActionResult Create(B b)
{
if (ModelState.IsValid)
{
db.B.Add(b);
db.SaveChanges();
return RedirectToAction("Index", "Backoffice");
}
return View(b);
}
The controllers are identical.
In table A the view shows the validation message for the not nullable fields while in table B it gets to the controller and throws an exception in the SaveChanges method.
I think you need to add data validation attribute
[Required(AllowEmptyStrings = false)] to your class properties.
I have 2 tables, Users and Employees
CREATE TABLE [dbo].[Users](
[UserID] [int] IDENTITY NOT NULL,
[Username] [nvarchar](8) NOT NULL,
[Activo] [bit] NOT NULL,
[UltimoAcesso] [datetime] NULL,
PRIMARY KEY (UserID)
)
CREATE TABLE [dbo].[Employees](
[ColaboradorID] [int] IDENTITY(1,1) NOT NULL,
[Nome] [nvarchar](100) NOT NULL,
[Email] [nvarchar](100) NULL,
[UserID] [int] NULL
PRIMARY KEY(ColaboradorID),
UNIQUE (UserID)
)
ALTER TABLE [dbo].[Employees] WITH CHECK ADD CONSTRAINT [FK_Employees_UtilizadorID] FOREIGN KEY([UserID])
REFERENCES [dbo].[Users] ([UserID])
ON UPDATE CASCADE
ON DELETE CASCADE
I'm using Entity FrameWork Database first.
I'm trying to insert a new user
public void fvAddUser_InsertItem()
{
var item = new InventarioCiclico.Users();
using (InventarioCiclicoContext db = new InventarioCiclicoContext())
{
Employee c = new Employee ();
c.Nome = (fvAddUser.FindControl("txtNome") as TextBox).Text;
c.Email = (fvAddUser.FindControl("txtEmail") as TextBox).Text;
item.Employee.Add(c);
var employee = db.Set<Employee>();
TryUpdateModel(item);
if (ModelState.IsValid)
{
if (db.Users.Any(u => u.Username == item.Username))
{
// Handle exception
}
else
{
db.Users.Add(item);
db.SaveChanges();
var userID = item.UserID;
c.UserID = userID;
employee.Add(c);
db.SaveChanges();
}
}
}
}
However it keeps giving me exception of violation of unique value? Before starting with entity framework I would insert on Users table first, get scope_identity and insert on Employee table after and I'm trying to do this using EF6 but i don't know what can i do about this.
You are adding two employees with the same UserId in the database and since UserId is a unique field in employee table you are getting the exception of violation of unique value.
In the line item.Employee.Add(c); you are add the employee to the user, therefore, when adding the user to the database, the employee will be added two. So you don't need the last three lines:
c.UserID = userID;
employee.Add(c);
db.SaveChanges();
I am a student and working on a college project.
I have created a simple scenario which I am facing in my project.
The simple database looks like this.
**Location Table**
CREATE TABLE [dbo].[Location] (
[Id] INT IDENTITY (1, 1) NOT NULL,
[longitude] VARCHAR (50) NULL,
[latitude] VARCHAR (50) NULL,
PRIMARY KEY CLUSTERED ([Id] ASC)
);
**Role Table**
CREATE TABLE [dbo].[Role] (
[Id] INT IDENTITY (1, 1) NOT NULL,
[Name] VARCHAR (50) NULL,
PRIMARY KEY CLUSTERED ([Id] ASC)
);
**Another table**
CREATE TABLE [dbo].[Another] (
[Id] INT IDENTITY (1, 1) NOT NULL,
[Anything] VARCHAR (50) NULL,
PRIMARY KEY CLUSTERED ([Id] ASC)
);
**User Table**
CREATE TABLE [dbo].[User] (
[Id] INT IDENTITY (1, 1) NOT NULL,
[name] VARCHAR (50) NULL,
[address] VARCHAR (50) NULL,
[loc_id] INT NOT NULL,
[role_id] INT NOT NULL,
[another_id] INT NOT NULL,
PRIMARY KEY CLUSTERED ([Id] ASC),
CONSTRAINT [FK_User_lococation] FOREIGN KEY ([loc_id]) REFERENCES [dbo].[Location] ([Id]),
CONSTRAINT [FK_User_another] FOREIGN KEY ([another_id]) REFERENCES [dbo].[Another] ([Id]),
CONSTRAINT [FK_User_role] FOREIGN KEY ([role_id]) REFERENCES [dbo].[Role] ([Id])
);
I have populated Role table with following values
enter image description here
Now I want to add user using EntityFrameWorkCore
My controller looks like this
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create([Bind("Id,Name,Address,RoleId")] User user)
{
if (ModelState.IsValid)
{
_context.Add(user);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Index));
}
ViewData["LocId"] = new SelectList(_context.Location, "Id", "Id", user.LocId);
ViewData["RoleId"] = new SelectList(_context.Role, "Id", "Id", user.RoleId);
return View(user);
}
The problem is I want to Add User but it doesn't have a foreign key of Location table and Another table.
How can I create a Location_id and Another_id and put in User
I want my User object to get the foreign key of location table and another table.
Please help me, I don't know how to do that it will great help for me.Thanks
If you don't have info about FK, don't generate it randomly, make foreign key column nullable in class user. Surely, when you are using EF you have navigation properties in User class. You can add also int property which stores id of associated entity (this is advised, so if you don't have, create such property). Type of this property should (obviously) nullable, so use int?. Then update database, so FK column in DB will be also nullable. Then you will be able to insert user entity.
I have ASP.NET MVC app
I have two relative tables Companies and Vacancies.
When I delete Company, I want to delete relative to it Vacancies.
Here is my controller
public ActionResult Delete(int? id)
{
if (id == null)
{
return new HttpStatusCodeResult(HttpStatusCode.BadRequest);
}
Company companies = db.Companies.Find(id);
if (companies == null)
{
return HttpNotFound();
}
return View(companies);
}
// POST: Companies/Delete/5
[HttpPost, ActionName("Delete")]
[ValidateAntiForgeryToken]
public ActionResult DeleteConfirmed(int id)
{
Company companies = db.Companies.Find(id);
db.Companies.Remove(companies);
db.SaveChanges();
return RedirectToAction("Index");
}
And here is Companies table
CREATE TABLE [dbo].[Companies] (
[CompanyID] INT IDENTITY (1, 1) NOT NULL,
[CompanyName] NVARCHAR (MAX) NULL,
PRIMARY KEY CLUSTERED ([CompanyID] ASC)
);
AnŠ² vacancies
CREATE TABLE [dbo].[Vacancies] (
[VacancyId] INT IDENTITY (1, 1) NOT NULL,
[VacancyName] NCHAR (10) NULL,
[CompanyID] INT NULL,
PRIMARY KEY CLUSTERED ([VacancyId] ASC),
CONSTRAINT [FK_Vacancies_ToTable] FOREIGN KEY ([CompanyID]) REFERENCES [dbo].[Companies] ([CompanyID])
);
How I need to modify my syntax to easily delete company?
Modify your dependent to add ON DELETE CASCADE
CREATE TABLE [dbo].[Vacancies] (
[VacancyId] INT IDENTITY (1, 1) NOT NULL,
[VacancyName] NCHAR (10) NULL,
[CompanyID] INT NULL,
PRIMARY KEY CLUSTERED ([VacancyId] ASC),
CONSTRAINT [FK_Vacancies_ToTable]
FOREIGN KEY ([CompanyID])
REFERENCES [dbo].[Companies] ([CompanyID])
ON DELETE CASCADE);
This will allow delete your references when you delete you're company.
Alternatively you can mark each entity as deleted from C#, this will give you more control and avoid accidental deletes