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Using identity with Web API

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Part 19 - Call web api service with basic authentication using jquery ajax
Part 20 - ASP.NET Web API token authentication
Part 21 - ASP.NET Web API user registration

In this video we will discuss customizing and using identity server with Web API. This is continuation to Part 21. Please watch Part 21 from ASP.NET Web API tutorial before proceeding.

In our previous video we have seen that the database that the identity system creates has a strange name. 

First let us understand the different tables that we have in the database and their purpose
Table Description
__MigrationHistory The presence of this table tells us that it is using entity framework
AspNetRoles Store roles information. We do not have any roles yet so this table is empty
AspNetUserClaims We do not have claims, so this table will also be empty
AspNetUserLogins This table is for third party authentication providers like Twitter, Facebook. Microsoft etc. Information about those logins will be stored in this table
AspNetUserRoles This is a mapping table which tells us which users are in which roles
AspNetUsers This table stores the registered users of our application

At this point the obvious question that comes to our mind is, is it possible to change the database name. If so, how can we do it?

The DefaultConnection string in web.config controls the name of the generated database. To change the name of the generated database change the DefaultConnection string in web.config. 

For example, if you want to name the database - UsersDB, change the DefaultConnection string as shown below
<add name="DefaultConnection"
  connectionString="Data Source=(LocalDb)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\UsersDB.mdf;Initial Catalog=UsersDB;Integrated Security=True"
  providerName="System.Data.SqlClient" />

Save the changes and when you run the application, identity system will create a database with name UsersDB. But at this point the database is still created in App_Data folder. Another question that comes to our mind is can we create this database in SQL Server.

The answer is, YES we can. To create the database in SQL Server, change the DefaultConnection string in web.config to point to your SQL Server. Notice I have changed 
Data Source value from (LocalDb)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\UsersDB.mdf to (local). You can also use . (DOT) instead of the word (local).

With the above change, the connection string in web.config is as shown below
<add name="DefaultConnection"
      connectionString="Data Source=(local);Initial Catalog=UsersDB;Integrated Security=True"
      providerName="System.Data.SqlClient" />

At this point when we save the changes and run the application the database (UsersDB) is created in SQL Server instead of App_Data folder. Make sure, you refresh the Databases folder in SQL Server Management Studio to see the newly created UsersDB database.

Is it mandatory for the Identity tables to be in a separate database. Can't we have them created in an existing database.
No it is not mandatory for the Identity tables to be in a separate database. You can have them created by Identity framework in an existing database by just making your connection string point to your existing database instead of a separate database.

For example, if we want the identity tables to be created in EmployeeDB, we will change the DefaultConnection string to point to EmployeeDB as shown below.
<add name="DefaultConnection"
     connectionString="Data Source=(local);Initial Catalog=EmployeeDB;Integrated Security=True"
     providerName="System.Data.SqlClient" />

ASP.NET Identity system can be used with all of the ASP.NET frameworks, such as ASP.NET MVC, Web Forms, Web API, and SignalR. It can be used when you are building web, phone, store, or hybrid applications.

In our next video we will discuss implementing Login page.

ASP.NET Web API tutorial for beginners


  1. Hi Venkat, It will be great if you could please explain to me how to use existing Users Table in Oracle DB with Identity Entity Framework DataBase Fist Approach.


  2. Unable to find the UsersDB in sql server management studio. But api is success. When registering with same email its showing error also that email is already taken.

  3. Hi ! I have a problem. Everything works perfect until moment when we change Data Source=(local) od dot.
    I getting an error: "cant find server, can't open connection with sql server. I tried to fix it, but still not working. Do you know what is wrong?

    1. Use: \sqlexpress
      e.g. My Computer name is PC161
      Hence, Data Source=PC161\SQLEXPRESS
      You will find computer name on following location: Control Panel => System
      'sqlexpress' is the instance name unless the name was changed during setup of Microsoft SQL Management Studio.

  4. thanks for all the knowledge transmitted

  5. Nice information !
    Working well using Visual Studio Express 2015 & Microsoft SQL Server Management Studio Version 12.


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