In this post I am going to look at one of the most anticipated features, Model First.  In the first version of the Entity Framework, you took a pre-existing database and the tools would generate your entity model for you.  In v2.0, you now have the option of creating your entity model first and then generating your database DDL from your finished model.

To follow this tutorial you will need Visual Studio 2010 Beta 1, .Net Framework 4.0 Beta 1 installed, SQL 2005 or 2008 / SQL Express.

Please bear with me and let me know if there are any parts of this tutorial that are not completely clear.  I am new to writing these! So any comments welcome….

Creating your project and adding your blank entity model

Open Visual Studio 2010 and create a new Dynamic Data Entities Web Application project(you could another project type to host your entity model, such as an ASP.Net Web Application).

Once your project has been created add a new ADO.Net Entity Data Model to the project. 

You will then be asked about what the model should contain.  As with version 1 of the Entity Framework, you have two options, Generate from Database and Empty Model.  To a large extent, the latter was redundant in the first version of the framework, but with version 2 it becomes very useful.  Select Empty Model and click Finish.

Adding an entity and scalar properties to your model

You will now be presented with your empty model designer ready for you to add your entities.  Right click on the designer and select Add –> Entity…  For this example we will name our entity “Customer” and the entity set “Customers”.  This will create your Customer entity in the designer.

You will now need to add some properties to the entity.  You can do this by right clicking the entity and Add –> Scalar Property and then selecting the data type of the property. Do this and create two string scalar properties for Name and Email.

Adding complex types

You should now have a Customer entity with properties for the customer’s name and email address. A complex type is essentially a property that can contain sub properties.  To display this we are going to create one for the customer’s mailing address.

In your model browser, right click on the “Complex Types” folder and select Create Complex Type.  Rename this created type “Address”.  Now right click on the Address object you have created and select Add –> Scalar Property –> String.  Rename the created property “Line 1”.  Repeat this, adding properties for Line 2, Town, County, Post Code (you could use City, State, Zip if you are in the U.S. for example).

Once you have created your complex type, you can add this to your Customer entity by right clicking the entity and selecting Add –> Complex Property. If you name your property Address, then the property type should automatically be set to Address, which is what we have just created.  You can check this and alter the type via the properties of the complex property (that’s a lot of properties )

Create some additional entities

Once I had created my Customer entity, I then went through the same steps to create two additional entities for Order and Product. If you do this, then you should end up with something like below.

Adding entity associations

Now that we have our entities for Customer, Order and Product, we need to tell the model how the entities are associated.  For example, a customer will have related orders and an order will have related products.

To add our first association, right click the Customer entity and select Add –> Association. You will then be presented with the dialog shown below to actually define the association.  As you can see, the primary entity for this association is Customer which is related to Order with a multiplicity of one-to-many.  Here is where we also set the navigation properties which will allow us to access related entities.  So for example, the Customer entity will have a navigation property of “Orders”.  There is also a plain English description of the association you are about to create to ensure that you are creating it correctly.

Once you are happy click ok and the association will be shown on your model connecting the Customer and Order entities.

We now need to also create an association between the Order and Product entities using the same steps as above, but this time the properties of the association are slightly different as the multiplicity is many-to-many as show below.

Generating the database

Ok, so we have our model containing our entities.  Our entities have their properties and their associations, but we still do not have a database for our model to map to.  This is the bit I really like.  Right click on the model designer area and click “Generate Database Script From Model…”.

This will then open the standard database connection dialog we are all used to in Visual Studio. Add a connection, select your server and enter a name for your database (use a name that does not already exist, I called mine “ModelFirstTestDb”…..original I know!), then click OK.  You should then be prompted to create the database as seen below, so click Yes to create the database.

You should now see your new connection selected and the option to store the credentials in the web.config should be checked. Click next and the database schema scripts (DDL) will be generated for you and you will be presented with the generated script as below.  Take a minute to have a look through the DDL and see how it has created the tables and fields.  In the image below you can see the fields that have been generated to map to the complex type for the Customer address we created earlier.

Now we just need to click Finish and we will be warned that our existing mappings and store schema will be overwritten, click Yes to continue.

Execute your DDL

Now you need to take the generated script and execute it against your database.  The database itself will have been created, but in this beta version you still need to execute the scripts manually.  The ADO.Net team have indicated that this will not be the case in the final version.

Running your Dynamic Data Entities application

If you now open the Global.asax.cs file in your project and add the following line in the RegisterRoutes method, you should be able to run your application and see your new model and database in action;

DefaultModel.RegisterContext(typeof(Model1Container),new ContextConfiguration() { ScaffoldAllTables = true });

Technorati Tags: .net 4, ado.net, Entity Framework, tutorial, visual studio 2010

In this tutorial series I am going to focus on the Dynamic Data controls within the extensions and try and give some guidance on what Dynamic Data is, what it can do for you and how to do it.

In this post, Part 1, I am going to discuss what Dynamic Data is and how you can very quickly create something functional.  In future posts I will look at some of the more advanced topics and techniques available.

This is my first tutorial series, so please do post any comments you have (good or bad )!

What is Dynamic Data?

Dynamic Data is extremely cool.  In short, it allows a developer to create a data driven web application that allows you view data within a database, insert, update and delete records, all rounded off with automated validation to go with it.  “Great…but I can already do that”, I hear you say, well that’s the best bit, the whole process of getting a web application, with master / detail web forms and full editing capabilities, up and running only takes a couple of minutes!

Once created, the resulting application can be customised very easily in order to display data to suit your needs, modify the way in which input occurs , for example, wherever the user inserts or edits a date field, you might want to have a Microsoft .Net Calendar Control instead of having them type the date in manually. You can also set logic on your database fields from within the application.  For example, you might want to add a range to an integer field or check for a pattern within a string using regular expressions.  Again, this is all possibly and relatively simple to accomplish.

Ok, so you know what Dynamic Data is now, so lets have a look at what you need to create a Dynamic Data web site and follow this tutorial.

Downloading the preview and getting the right tools

Firstly, for this tutorial you are going to need a copy of either Visual Studio 2008, or Visual Web Developer Express 2008.  Visual Studio Web Developer Express 2008 is a free IDE from Microsoft for developers to use, if you don’t have a copy of Visual Studio then I would definitely suggest checking out the Express edition web site here.

Next you need to download and install the ASP.NET 3.5 Extensions from here.  This package contains different parts that make up the extensions, so of which are now outdated, so you will also need to download the latest release of the ASP.NET Dynamic Data controls from here.

Of course, as we are going to create a data driven web site, you need a database. If you don’t already have it, go and download a copy of SQL Server 2005 Express Edition from here.  You can use any database with this tutorial, but I am using the Adventure Works sample database for SQL Server 2005 available from here (it is the top link that you will need, AdventureWorksDb.msi).

I won’t go into setting up your sample database here, or installing / configuring SQL Server and Visual Studio.  If you need any help though, the web is awash with assistance, just do a Google search and you’re sure to find a tutorial / tips site to help you.  Obviously, there is supporting documentation for everything as well.

Building your first Dynamic Data Web Site

1.  Open Visual Studio / Visual Web Developer.  By now you should have all of the necessary preview extensions & controls installed.  Select File -> New Web Site.  Now that you have installed the Dynamic Data preview installed you will notice that there is now a couple of new project templates available for you to use and for this example we are going to use the Dynamic Data Web Application template as shown below.

2.  Now we need to establish a connection to the database.  To do this, click on View -> Server Explorer. Once the Server Explorer tab is open, right click within it and select New Connection.

You should then see a connection settings window shown to the right.

Enter your database server details here and select the database you wish to work with.

3.  Now that we have configured our database connection, we should now be able to see our database listed within the server explorer and you should have a tree view of your database where you can see your tables, views, stored procs etc.Now, we have to define our data model.  Sound scary? Well don’t worry, because this is painfully easy as well.Within your Solution Explorer, right click on the project name and select Add New Item…

You will notice that you will now be able to select a “LINQ to SQL Classes” item.  

Add one of these items and you will be asked if you want to create an APP_CODE folder, say YES to this as this is required for your data model.

4.  Once Visual Studio / Visual Web Developer has finished creating the new LINQ to SQL Classes item, you will be presented with a blank window for the new item (.dbml file).  To create your model, simply drag the tables you want in your web site from your database in Server Explorer into this window like below.  You will notice that will even persist the table relationships already setup with your database.

I have chosen to drag the tables associated with Person information into my model.When you are happy with your selection, save this dbml file.

5.  The one last thing we need to do before our new data driven web application will work is to edit a line in our configuration file.  The security minded people at Microsoft have switched off the automatic creation of all table ‘scaffolding’ by default and we need to enable it.  We are going to enable it for all tables in the model, but in a real world situation you would enable it only for tables you actually wanted to expose though this method.Open your Web.Config file and amend the following line to read as true like below.

<dynamicData dataContextType=“” enableTemplates=“true”>

6.  Now run your web application and hopefully, you should have a functional web application that allows you to View, Insert, Edit and Delete information within your database, like the one below.

What’s Next

Now that you have your working application, have a good look around.  In the next part of this series, we will look at the application itself and what you have got right out of the box and point out a few things that you might not have noticed.

Technorati Tags: .net 3.5, Dynamic Data, sql server