I made some changes to my models, these included adding a new field to a class and creating a new class (table), as shown below:
using System;
using System.Collections.Generic;
using System.ComponentModel.DataAnnotations;
using System.IO;
using System.Linq;
using Newtonsoft.Json;
namespace SurveyTool.Models
{
public class Industry
{
[Key]
public int ID { get; set; }
public string name { get; set; }
}
}
When I Add-Migration and Update-Database, the new field was added. However, the new table wasn't. I tried the process again and the newest migration is empty.
Why isn't the standard process for adding a new table working?
Thanks!
Related
I created my initial project in Visual Studio and discovered I had used SQL Server after I created my initial migration. I then changed all the connection information to use MYSQL and connected successfully. I created the initial migration again and it created all the ASP security tables. I added a new model and updated the database, but it created an empty migration (just UP/DOWN methods)
I've tried multiple fixes I found here and other sites. I backed out the second migration and retried. I tried forcing the migration again (-f). I dropped the new MYSQL db and deleted the migrations then started over, all with the same result.
Here is my model code:
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace congresssucks_conversion.Models
{
public class BlogPost : DBContext
{
public int Id { get; set; }
public string Title { get; set; }
public string ShortPost { get; set; }
public string Post { get; set; }
public string Tags { get; set; }
public DateTime Updated { get; set; }
}
}
And here is the migration file:
namespace congresssucks_conversion.Migrations
{
using System;
using System.Data.Entity.Migrations;
public partial class blogpost : DbMigration
{
public override void Up()
{
}
public override void Down()
{
}
}
}
It completes successfully and no errors in the Terminal Window.
You're combining two separate things, your model class and your database context.
Your BlogPostm class shouldn't inherit DbContext, it should be just a plain C# class.
Then you make a new class that looks something like this:
public class BlogDbContext : DbContext
{
public DbSet<BlogPostm> Posts { get; set; }
}
Now you have a class that can represent a single post, and another class that can represent a database with a table of multiple blog posts. The migration generator is looking for those DbSet<whatever> properties, so you should see real migrations after this change.
There are a lot more ways you can describe what you want Entity Framework to do with your database, so it would be worth reviewing an Entity Framework tutorial.
Try to delete a record of last migration from _MigrationHistory table. Maybe This record had been incorrectly created before added DbSet for the new model object to DbContext class. After this delete, new migration was created with correct Up() and Down() methods.
I am currently building an MVC site using Entity Framework. I have created following class:
using System; using System.Collections.Generic;
using System.Linq; using System.Web;
using System.ComponentModel.DataAnnotations.Schema;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel;
namespace .Models {
public class VehicleTableData
{
[NotMapped]
public Dictionary<string,string> StandardVehicleData { get; set; }
[NotMapped]
public Dictionary<string,string> AdditionalData { get; set; }
} }
However, I would like it to be ignored by Entity Framework as when I try to create a view with it I get the error that there is no valid key.
If you have the class defined in your DbContext with the following line of code:
public DbSet<VehicleTableData> VehicleTableDatas { get; set; }
This will cause Entity Framework to include the class. Once the above line is removed it will not be included.
You could also remove the [NotMapped] attributes as this would only apply to properties that you would not want saved to the database in a model included in your DbContext.
I've already read several SO questions about this topic, but honestly most of them have been way too complex for me. I'm very new to ASP.NET mvc.
I have a sample ASP.NET mvc 4 app that I created by following along with (and deviating just a bit from) the Movie database tutorial. It has the built-in account bits, the Entity Framework (which has turned out to be a pain any time I change anything) plus 2 models that I built myself based on the models from the tutorial:
1) Bug
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity;
namespace MasterDetailPractice.Models
{
public class Bug
{
public int BugID { get; set; }
public string BugTitle { get; set; }
public DateTime BugDate { get; set; }
public string BugStatus { get; set; }
[Column(TypeName = "ntext")]
[MaxLength]
public string BugDescription { get; set; }
}
public class BugDBContext : DbContext
{
public DbSet<Bug> Bugs { get; set; }
public DbSet<Comment> Comments { get; set; }
}
}
2) Comment
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.ComponentModel.DataAnnotations;
using System.ComponentModel.DataAnnotations.Schema;
using System.Data.Entity;
namespace MasterDetailPractice.Models
{
public class Comment
{
public int CommentID { get; set; }
public int BugID { get; set; }
public int UserID { get; set; }
public DateTime CommentDate { get; set; }
[Column(TypeName = "ntext")]
[MaxLength]
public string CommentText { get; set; }
}
}
When I run my app I'm able to go to /Project and get the standard Index view with the Add link, where I can add a Bug. Once added, I see the usual Edit/Details/Delete links.
When I run my app I'm also able to go to /Comment and get the standard Index view with the Add link, where I can add a Comment. Once added, I see the usual Edit/Details/Delete links.
Up to this point, I'm OK. The CRUD forms work, they just don't work together.
THE PROBLEM:
Currently, in order to make a Comment apply to a Bug, I have to actually input a BugID into the /Comment/Create form. And then the Comments are all only available at the /Comment/ route.
Instead, I need the following to happen:
The "Add Comment" form should automatically know what BugID to
save without a user having to input it.
A master-detail presentation of the data: The /Comment/Index view should appear at the bottom of the /Bug/Edit and/or Bug/Details page and show only the Comments related to the current Bug.
The "Add Comment" link should only appear from the /Bug/Edit or
/Bug/Details page, so Comments are never added without relating to a Bug.
It's kind of amazing that I haven't been able to figure this out myself, after spending 3 days poring over every Google result and SO post I can find on the topic. That said, here I am, hoping to learn the simplest possible implementation of this.
Do I need to post more code (the Controllers, for example, or the Views) in order for this question to be properly answerable?
Looking forward to getting the slow-learning train to start pulling out of the station...
Okay you need to do a few things.
First, create a new action method in your CommentController that looks like this.
public ActionResult Index(int bugId)
{
// Your logic to fetch all comments by BugID through EntityFramework or whatever
return View(data);
}
Now, in your Bug/Edit.cshtml or Bug/Details.cshtml pages add the following line to render those actions inline.
#Html.RenderAction("Index", "Comment", new { #bugId = Model.BugID }
In this case, you should be returning a BugModel back to your Bug/Edit.cshtml or Bug/Details.cshtml anyway as your model.
This should show you the form you need, with the BugID from the model being passed through.
For your last question, just put the "Add Comment" link within your Comment/Index.cshtml view since it will only appear anyway within the context of a bug. You will probably need to wrap this around a form that posts to your CommentController.
Here's a helpful link on working with forms in ASP.NET 4.
http://www.asp.net/mvc/tutorials/hands-on-labs/aspnet-mvc-4-helpers,-forms-and-validation
I'm learning asp.net mvc3 from w3schools and following that tutorial.http://w3schools.com/aspnet/mvc_models.asp In the section "ASP.NET MVC Models" I have created the model like this.
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Data.Entity;
namespace MvcDemo.Models
{
public class MovieDB
{
public int ID { get; set; }
public string Title { get; set; }
public string Director { get; set; }
public DateTime Date { get; set; }
}
public class MovieDBContext : DbContext
{
public DbSet<MovieDB> Movies { get; set; }
}
}
Then I was going to add a controller according to the instructions.
In the Solution Explorer, right-click the Controllers folder, and select Add and Controller
Set controller name to MoviesController
Select template: Controller with read/write actions and views, using Entity Framework
Select model class: MovieDB (McvDemo.Models)
Select data context class: MovieDBContext (McvDemo.Models)*
Select views Razor (CSHTML)
Click Add
But the problem I have is that the drop down list doesn't show MovieDB (McvDemo.Models) in Model Class and Data Context Class to be selected. Can anyone please help me? Thanks.
You should just be able to recompile (Shift-Ctrl-B) and then try it again - it will be there. Otherwise you can always just declare it yourself at the top of a blank view, but that will not provide the scaffolding that the generator does:
#model MvcDemo.Models.MovieDB;
I recompiled but that did not fix the issue for me and yes I am doing the same thing and ran into the same exact issue. The problem for me was caused by visual web developer not being able to connect to my Movies database. I had to change the definition of my connectionString within web.config like this:
<add name="MovieDBContext"connectionString="Data Source=c:\sites\w3schools_demo\MvcDemo2\MvcDemo2\App_Data\Movies.sdf" providerName="System.Data.SqlServerCe.4.0"/>
If you are having this issue you will need to change the "Data Source" path to point to your Movies.sdf database file.
Going mad now. I have a MVC solution that i've upgraded from MVC 1 to 2. It all works fine.... except the Validation!
Here's some code:
In the controller:
using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Security.Principal;
using System.Web;
using System.Web.Mvc;
using System.Web.Security;
using System.Web.UI;
using MF.Services.Authentication;
using System.ComponentModel;
using System.ComponentModel.DataAnnotations;
namespace MF.Controllers
{
//basic viewmodel
public class LogOnViewData
{
[Required]
public string UserName { get; set; }
[Required]
public string Password { get; set; }
}
[HandleError]
public class AccountController : Controller
{
[HttpPost]
public ActionResult LogOn(LogOnViewData lvd, string returnUrl)
{
if (ModelState.IsValid)
{
//do stuff - IsValid is always true
}
}
}
}
The ModelState is always valid. The model is being populated correctly however. Therefore, if I leave both username and password blank, and post the form the model state is still valid. Argh!
Extra info: using structure map for IoD. Previously, before upgrading to MVC 2 was using the MS data annotation library so had this in my global.asax.cs:
ModelBinders.Binders.DefaultBinder = new Microsoft.Web.Mvc.DataAnnotations.DataAnnotationsModelBinder();
Have removed that now.
I'm sure i'm doing something really basic and wrong. If someone could point it out that would be marvellous.
Cheers
Half way through the development of MVC2, they went from input validation to model validation, which should in all cases validate your object completely. Make sure you're using the latest version (RTM).
However, [Required] merely indicates the attribute must not be null. Unfortunately, String.Empty -which is the default for strings- is not null, so model validation will pass for empty strings.
See this post by Brad Wilson for important details.
As a solution, you could use the [RegularExpression("....")] to impose restrictions on the minimum string length and allowed characters.