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#Adding a field to a report in microsoft visual studio 2005 movie
#Adding a field to a report in microsoft visual studio 2005 code

In the Package Manager Console window, enter the command add-migration Initial to create the initial migration. This migration creates a new database, that's why you deleted the movie.mdf file in a previous step. The next step is to create a DbMigration class for the initial migration. Press CTRL-SHIFT-B to build the project.(The following steps will fail if you don't build at this point.) If you manually add a duplicate title, you'll get the following exception the next time you perform a migration.įor more information about the AddOrUpdate method, see Take care with EF 4.3 AddOrUpdate Method.

#Adding a field to a report in microsoft visual studio 2005 code

This code assumes that titles are unique.

#Adding a field to a report in microsoft visual studio 2005 movie

For the test movie data that you are providing, the Title property can be used for this purpose since each title in the list is unique: (i => i.Title, The first parameter passed to the AddOrUpdate method specifies the property to use to check if a row already exists. In that case you want to do a conditional insert operation: insert a row only if it doesn't already exist. With test data in some tables you might not want that to happen: in some cases when you change data while testing you want your changes to remain after database updates. The " upsert" operation prevents errors that would happen if you try to insert a row that already exists, but it overrides any changes to data that you may have made while testing the application. The AddOrUpdate method in the following code performs an "upsert" operation: (i => i.Title,īecause the Seed method runs with every migration, you can't just insert data, because the rows you are trying to add will already be there after the first migration that creates the database. Hover over the red squiggly line under Movie and click Show Potential Fixes and then click using MvcMovie.Models ĭoing so adds the following using statement: using MvcMovie.Models Ĭode First Migrations calls the Seed method after every migration (that is, calling update-database in the Package Manager Console), and this method updates rows that have already been inserted, or inserts them if they don't exist yet. Replace the Seed method in the Configuration.cs file with the following code: protected override void Seed( context)Ĭ( i => i.Title, Visual Studio opens the Configuration.cs file. The Enable-Migrations command (shown above) creates a Configuration.cs file in a new Migrations folder. In the Package Manager Console window at the PM> prompt enterĮnable-Migrations -ContextTypeName If you don't see the Movies.mdf file, click on the Show All Files icon shown below in the red outline.īuild the application to make sure there are no errors.įrom the Tools menu, click NuGet Package Manager and then Package Manager Console. Right click on the Movies.mdf file and select Delete to remove the movies database. Setting up Code First Migrations for Model Changes This makes it easier to track down issues at development time that you might otherwise only find (by obscure errors) at run time. If they aren't in sync, the Entity Framework throws an error. In this section you'll use Entity Framework Code First Migrations to migrate some changes to the model classes so the change is applied to the database.īy default, when you use Entity Framework Code First to automatically create a database, as you did earlier in this tutorial, Code First adds a table to the database to help track whether the schema of the database is in sync with the model classes it was generated from.

Is the preferred approach for new app development.

We recommend you try the Razor Pages tutorial before the MVC version. Razor Pages is a new alternative in ASP.NET Core, a page-based programming model that makes building web UI easier and more productive. This tutorial teaches ASP.NET Core MVC with controllers and views. The new tutorial uses ASP.NET Core MVC, which provides many improvements over this tutorial. How you do this doesn't matter, but here's an example: DataSet ds = GeneratePickingNoteDataSet(id) įoreach (DataRow row in ds.Tables.An updated version of this tutorial is available here using the latest version of Visual Studio. This class is manually filled by me by manually retrieving data from the database. I created a class to hold the data for my report. In the report designer '.Net Objects' are used, rather than communicating with the database. The ArrayList is bound to the report viewer, along with the name of the report to load. This is then instantiated and filled with data and then placed inside an ArrayList. It works by having a 'data class' which is just a regular C# class containing variables and no code.