Creating the Membership Schema in SQL Server (C#)
This tutorial starts by examining techniques for adding the necessary schema to the database in order to use the SqlMembershipProvider. Following that, we will examine the key tables in the schema and discuss their purpose and importance. This tutorial ends with a look at how to tell an ASP.NET application which provider the Membership framework should use.
The previous two tutorials examined using forms authentication to identify website
visitors. The forms authentication framework makes it easy for developers to log
a user into a website and to remember them across page visits through the use of
authentication tickets. The
FormsAuthentication class includes methods
for generating the ticket and adding it to the visitor's cookies. The
examines all incoming requests and, for those with a valid authentication ticket,
creates and associates a
GenericPrincipal and a
object with the current request. Forms authentication is merely a mechanism for
granting an authentication ticket to a visitor when logging in and, on subsequent
requests, parsing that ticket to determine the user's identity. For a web application
to support user accounts, we still need to implement a user store and add functionality
to validate credentials, register new users, and the myriad of other user account-related
Prior to ASP.NET 2.0, developers were on the hook for implementing all of these user account-related tasks. Fortunately the ASP.NET team recognized this shortcoming and introduced the Membership framework with ASP.NET 2.0. The Membership framework is a set of classes in the .NET Framework that provide a programmatic interface for accomplishing core user account-related tasks. This framework is built atop the provider model, which allows developers to plug a customized implementation into a standardized API.
As discussed in the Security Basics and ASP.NET Support tutorial, the
.NET Framework ships with two built-in Membership providers:
SqlMembershipProvider. As its name implies, the
uses a Microsoft SQL Server database as the user store. In order to use this provider
in an application, we need to tell the provider what database to use as the store.
As you might imagine, the
SqlMembershipProvider expects the user store
database to have certain database tables, views, and stored procedures. We need
to add this expected schema to the selected database.
This tutorial starts by examining techniques for adding the necessary schema to
the database in order to use the
SqlMembershipProvider. Following that,
we will examine the key tables in the schema and discuss their purpose and importance.
This tutorial ends with a look at how to tell an ASP.NET application which provider
the Membership framework should use.
Let's get started!
Step 1: Deciding Where to Place the User Store
An ASP.NET application's data is commonly stored in a number of tables in a database.
When implementing the
SqlMembershipProvider database schema we must
decide whether to place the Membership schema in the same database as the application
data or in an alternate database.
I recommend locating the Membership schema in the same database as the application data for the following reasons:
- Maintainability � an application whose data is encapsulated in one database is easier to understand, maintain, and deploy than an application that has two separate databases.
- Relational Integrity � by locating the Membership-related tables in the same database as the application tables it is possible to establish foreign key constraints between the primary keys in the Membership-related tables and related application tables.
Decoupling the user store and application data into separate databases only makes sense if you have multiple applications that each use separate databases, but need to share a common user store.
Creating a Database
The application we have been building since the second tutorial has not yet needed
a database. We need one now, however, for the user store. Let's create one and then
add to it the schema required by the
(see Step 2).
Note: Throughout this tutorial series we will be using a
Microsoft SQL Server 2005 Express Edition database to store our application
tables and the
SqlMembershipProvider schema. This decision was made
for two reasons: first, due to its cost - free - the Express Edition is the most
readably accessible version of SQL Server 2005; second, SQL Server 2005 Express
Edition databases can be placed directly in the web application's
folder, making it a cinch to package the database and web application together in
one ZIP file and to redeploy it without any special setup instructions or configuration
options. If you'd prefer to follow along using a non-Express Edition version of
SQL Server, feel free. The steps are virtually identical. The
schema will work with any version of Microsoft SQL Server 2000 and up.
From the Solution Explorer, right-click on the
App_Data folder and
choose to Add New Item. (If you do not see an
App_Data folder in your
project, right-click on the project in Solution Explorer, select Add ASP.NET Folder,
App_Data.) From the Add New Item dialog box, choose to add
a new SQL Database named
SecurityTutorials.mdf. In this tutorial we
will add the
SqlMembershipProvider schema to this database; in subsequent
tutorials we will create additional tables to capture our application data.
Adding a database to the
App_Data folder automatically includes it
in the Database Explorer view. (In the non-Express Edition version of Visual Studio,
the Database Explorer is called the Server Explorer.) Go to the Database Explorer
and expand the just-added
SecurityTutorials database. If you do not
see the Database Explorer on screen, go to the View menu and choose Database Explorer,
or hit Ctrl+Alt+S. As Figure 2 shows, the
is empty - it contains no tables, no views, and no stored procedures.
Step 2: Adding the
SqlMembershipProvider Schema to the Database
SqlMembershipProvider requires a particular set of tables, views,
and stored procedures to be installed in the user store database. These requisite
database objects can be added using the
aspnet_regsql.exe tool. This file is located in the
aspnet_regsql.exe tool offers both command line functionality
and a graphical user interface. The graphical interface is more user friendly and
is what we will examine in this tutorial. The command line interface is useful when
the addition of the
SqlMembershipProvider schema needs to be automated,
such as in build scripts or automated testing scenarios.
aspnet_regsql.exe tool is used to add or remove ASP.NET application
services to a specified SQL Server database. The ASP.NET application services
encompass the schemas for the
along with the schemas for the SQL-based providers for other ASP.NET 2.0 frameworks.
We need to provide two bits of information to the
- Whether we want to add or remove application services, and
- The database from which to add or remove the application services schema
In prompting for the database to use, the
aspnet_regsql.exe tool asks
us to provide the name of the server the database resides on, the security credentials
for connecting to the database, and the database name. If you are using the non-Express
Edition of SQL Server, you should already know this information, as it is the same
information you must provide through a connection string when working with the database
through an ASP.NET web page. Determining the server and database name when using
a SQL Server 2005 Express Edition database in the
however, is a bit more involved.
The following section examines a straightforward way for specifying the server and
database name for a SQL Server 2005 Express Edition database in the
folder. If you are not using SQL Server 2005 Express Edition feel free to skip ahead
to the Installing the Application Services section.
Determining the Server and Database Name for a SQL Server 2005 Express Edition Database
In order to use the
aspnet_regsql.exe tool we need to know the server
and database names. The server name is
Most likely, the InstanceName is
SQLExpress. However, if you
installed SQL Server 2005 Express Edition manually (that is, you did not install
it automatically while installing Visual Studio), then it is possible that you selected
a different instance name.
The database name is a bit trickier to determine. Databases in the
folder typically have a database name that includes a
globally unique identifier along with the path to the database file. We
need to determine this database name in order to add the application services schema
The easiest way to ascertain the database name is to examine it through SQL Server Management Studio. SQL Server Management Studio provides a graphical interface for managing SQL Server 2005 databases, but it does not ship with the Express Edition of SQL Server 2005. The good news is that you can download the free Express Edition of SQL Server Management Studio.
Note: If you also have a non-Express Edition version of SQL Server 2005 installed on your desktop then the full version of Management Studio is likely installed. You can use the full version to determine the database name, following the same steps as outlined below for the Express Edition.
Start by closing Visual Studio to ensure that any locks imposed by Visual Studio
on the database file are closed. Next, launch SQL Server Management Studio and connect
localhost\InstanceName database for SQL Server 2005 Express
Edition. As noted earlier, chances are the instance name is
For the Authentication option, select Windows Authentication.
After connecting to the SQL Server 2005 Express Edition instance, Management Studio
displays folders for the Databases, the Security settings, the Server Objects, and
so on. If you expand the Databases tab you will see that the
database is not registered in the database instance - we need to attach the
Right-click on the Databases folder and choose Attach from the context menu. This
will display the Attach Databases dialog box. From here, click the Add button, browse
SecurityTutorials.mdf database, and click OK. Figure 4 shows
the Attach Databases dialog box after the
has been selected. Figure 5 shows Management Studio's Object Explorer after the
database has been successfully attached.
As Figure 5 shows, the
SecurityTutorials.mdf database has a rather
abstruse name. Let's change it to a more memorable (and easier to type) name. Right-click
on the database, choose Rename from the context menu, and rename it
This does not change the filename, just the name the database uses to identify itself
to SQL Server.
At this point we know the server and database names for the
respectively. We are now ready to install the application services through the
Installing the Application Services
To launch the
aspnet_regsql.exe tool, go to the start menu and choose
into the textbox and click OK. Alternatively, you can use Windows Explorer to drill
down to the appropriate folder and double-click the
file. Either approach will net the same results.
aspnet_regsql.exe tool without any command line arguments
launches the ASP.NET SQL Server Setup Wizard graphical user interface. The wizard
makes it easy to add or remove the ASP.NET application services on a specified database.
The first screen of the wizard, shown in Figure 7, describes the purpose of the
The second step in the wizard asks us whether we want to add the application services
or remove them. Since we want to add the tables, views, and stored procedures necessary
SqlMembershipProvider, choose the Configure SQL Server for
application services option. Later, if you want to remove this schema from your
database, re-run this wizard, but instead choose the Remove application services
information from an existing database option.
The third step prompts for the database information: the server name, authentication
information, and the database name. If you have been following along with this tutorial
and have added the
SecurityTutorials.mdf database to
attached it to
localhost\InstanceName, and renamed it to
then use the following values:
- Windows authentication
After entering the database information, click Next. The final step summarizes the steps that will be taken. Click Next to install the application services and then Finish to complete the wizard.
Note: If you used Management Studio to attach the database and rename the
database file, be sure to detach the database and close Management Studio before
reopening Visual Studio. To detach the
right-click on the database name and, from the Tasks menu, choose Detach.
Upon completion of the wizard, return to Visual Studio and navigate to the Database
Explorer. Expand the Tables folder. You should see a series of tables whose names
start with the prefix
aspnet_. Likewise, a variety of views and stored
procedures can be found under the Views and Stored Procedures folders. These database
objects make up the application services schema. We will examine the membership-
and role-specific database objects in Step 3.
aspnet_regsql.exe tool's graphical user interface
installs the entire application services schema. But when executing
from the command-line you can specify what particular application services components
to install (or remove). Therefore, if you want to add just the tables, views, and
stored procedures necessary for the
aspnet_regsql.exe from the command-line. Alternatively,
you can manually run the appropriate subset of T-SQL create scripts used by
These scripts are located in the
folder with names like
InstallSqlState.sql, and so on.
At this point we have created the database objects needed by the
However, we still need to instruct the Membership framework that it should use the
SqlMembershipProvider (versus, say, the
and that the
SqlMembershipProvider should use the
database. We'll look at how to specify what provider to use and how to customize
the selected provider's settings in Step 4. But first, let's take a deeper look
at the database objects that were just created.
Step 3: A Look at the Schema's Core Tables
When working with the Membership and Roles frameworks in an ASP.NET application,
the implementation details are encapsulated by the provider. In future tutorials
we will interface with these frameworks via the .NET Framework's
Roles classes. When using these high-level APIs we do not need
to concern ourselves with the low-level details, like what queries are executed
or what tables are modified by the
Given this, we could confidently use the Membership and Roles frameworks without
having explored the database schema created in Step 2. However, when creating the
tables to store application data we may need to create entities that relate to users
or roles. It helps to have a familiarity with the
SqlRoleProvider schemas when establishing foreign key constraints
between the application data tables and those tables created in Step 2. Moreover,
in certain rare circumstances we may need to interface with the user and role stores
directly at the database level (instead of through the
Partitioning the User Store Into Applications
The Membership and Roles frameworks are designed such that a single user and role store can be shared among many different applications. An ASP.NET application that uses the Membership or Roles frameworks must specify what application partition to use. In short, multiple web applications can use the same user and role stores. Figure 11 depicts user and role stores that are partitioned into three applications: HRSite, CustomerSite, and SalesSite. These three web applications each have their own unique users and roles, yet they all physically store their user account and role information in the same database tables.
aspnet_Applications table is what defines these partitions. Each
application that uses the database to store user account information is represented
by a row in this table. The
aspnet_Applications table has four columns:
ApplicationId is of type
uniqueidentifier and is the table's primary key;
provides a unique human-friendly name for each application.
The other Membership- and Role-related tables link back to the
aspnet_Applications. For example, the
table, which contains a record for each user account, has an
foreign key field; ditto for the
aspnet_Roles table. The
field in these tables specifies the application partition the user account or role
Storing User Account Information
User account information is housed in two tables:
aspnet_Users table contains fields
that hold the essential user account information. The three most pertinent columns
UserId is the primary key (and of type
UserName is of type
nvarchar(256) and, along with the
password, makes up the user's credentials. (A user's password is stored in the
ApplicationId links the user account
to a particular application in
aspnet_Applications. There is a composite
ApplicationId columns. This ensures
that in a given application each UserName is unique, yet it allows for the same
UserName to be used in different applications.
aspnet_Membership table includes additional user account information,
like the user's password, email address, the last login date and time, and so forth.
There is a one-to-one correspondence between records in the
aspnet_Membership tables. This relationship is ensured by the
UserId field in
aspnet_Membership, which serves as the table's
primary key. Like the
ApplicationId field that ties this information to a particular
Password information is stored in the
aspnet_Membership table. The
SqlMembershipProvider allows for passwords to be stored in the database
using one of the following three techniques:
- Clear - the password is stored in the database as plain-text. I strongly discourage using this option. If the database is compromised - be it by a hacker who finds a back door or a disgruntled employee who has database access - every single user's credentials are there for the taking.
- Hashed - passwords are hashed using a one-way hash algorithm and a randomly generated salt value. This hashed value (along with the salt) is stored in the database.
- Encrypted - an encrypted version of the password is stored in the database.
The password storage technique used depends on the
settings specified in
Web.config. We will look at customizing the
SqlMembershipProvider settings in Step 4. The default behavior is to
store the hash of the password.
The columns responsible for storing the password are
PasswordFormat is a field of type
int whose value indicates the technique used for storing the password:
0 for Clear; 1 for Hashed; 2 for Encrypted.
PasswordSalt is assigned
a randomly generated string regardless of the password storage technique used; the
PasswordSalt is only used when computing the hash of the password.
Password column contains the actual password data, be
it the plain-text password, the hash of the password, or the encrypted password.
Table 1 illustrates what these three columns might look like for the various storage techniques when storing the password MySecret! .
Storage Technique<_o3a_p />
Note: The particular encryption or hashing algorithm used by the
is determined by the settings in the
<machineKey> element. We
discussed this configuration element in Step 3 of the Forms Authentication Configuration and Advanced Topics
Storing Roles and Role Associations
The Roles framework allows developers to define a set of roles and specify what
users belong to what roles. This information is captured in the database through
record in the
aspnet_Roles table represents a role for a particular
application. Much like the
aspnet_Users table, the
table has three columns pertinent to our discussion:
RoleId is the primary key (and of type
RoleName is of type
links the user account to a particular application in
There is a composite
UNIQUE constraint on the
ApplicationId columns, ensuring that in a given application each
role name is unique.
aspnet_UsersInRoles table serves as a mapping between users and
roles. There are only two columns -
- and together they make up a composite primary key.
Step 4: Specifying the Provider and Customizing Its Settings
All of the frameworks that support the provider model - such as the Membership and
Roles frameworks - lack implementation details themselves and instead delegate that
responsibility to a provider class. In the case of the Membership framework, the
Membership class defines the API for managing user accounts, but it
does not interact directly with any user store. Rather, the
class's methods hand off the request to the configured provider - we will be using
SqlMembershipProvider. When we invoke one of the methods in the
Membership class, how does the Membership framework know to delegate
the call to the
Membership class has a
Providers property that contains a reference to all of the
registered provider classes available for use by the Membership framework. Each
registered provider has an associated name and type. The name offers a human-friendly
way to reference a particular provider in the
while the type identifies the provider class. Moreover, each registered provider
may include configuration settings. Configuration settings for the Membership framework
many others. See Table 2 for a complete list of configuration settings used by the
Providers property's contents are specified through the web application's
configuration settings. By default, all web applications have a provider named
AspNetSqlMembershipProvider of type
This default Membership provider is registered in
type="System.Web.Security.SqlMembershipProvider, System.Web, Version=126.96.36.199, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a"
As the markup above shows, the
<membership> element defines the configuration settings
for the Membership framework while the
<providers> child element specifies the registered providers.
Providers may be added or removed using the
<remove> elements; use the
<clear> element to remove all currently registered
providers. As the markup above shows,
machine.config adds a provider
AspNetSqlMembershipProvider of type
In addition to the
type attributes, the
element contains attributes that define the values for various configuring settings.
Table 2 lists the available
settings, along with a description of each.
Note: Any default values noted in Table 2 refer to the default values defined
SqlMembershipProvider class. Note that not all of the configuration
AspNetSqlMembershipProvider correspond to the default values
SqlMembershipProvider class. For example, if not specified in
a Membership provider, the
requiresUniqueEmail setting defaults to
true. However, the
AspNetSqlMembershipProvider overrides this default
value by explicitly specifying a value of
Recall that the Membership framework allows for a single user store to be partitioned across multiple applications. This setting indicates the name of the application partition used by the Membership provider. If this value is not explicitly specified, it is set, at runtime, to the value of the application's virtual root path.
Specifies the SQL command timeout value (in seconds). The default value is 30.
The name of the connection string in the
Provides a human-friendly description of the registered provider.
Specifies whether users may retrieve their forgotten password. The default value
Indicates whether users are allowed to reset their password. Defaults to
The maximum number of unsuccessful login attempts that may occur for a given user
during the specified
The minimum number of non-alphanumeric characters that must appear in a user's password. This value must be between 0 and 128; the default is 1.
The minimum number of characters required in a password. This value must be between 0 and 128; the default is 7.
The name of the registered provider. This value is required.
The number of minutes during which failed login attempts are tracked. If a user
supplies invalid login credentials
The password storage format:
If provided, this regular expression is used to evaluate the strength of the user's selected password when creating a new account or when changing their password. The default value is an empty string.
Specifies whether a user must answer his security question when retrieving or resetting
his password. The default value is
Indicates whether all user accounts in a given application partition must have a
unique email address. The default value is
Specifies the type of the provider. This value is required.
In addition to
AspNetSqlMembershipProvider, other Membership providers
may be registered on an application-by-application basis by adding similar markup
Note: The Roles framework works in much the same way: there is a default
registered role provider in
machine.config and the registered providers
may be customized on an application-by-application basis in
We will examine the Roles framework and its configuration markup in detail in a
connectionStringName attribute set to
AspNetSqlMembershipProvider provider, the connection string
LocalSqlServer is defined in
connectionString="data source=.\SQLEXPRESS;Integrated Security=SSPI;AttachDBFilename=|DataDirectory|aspnetdb.mdf;User Instance=true"
As you can see, this connection string defines a SQL 2005 Express Edition database
located at |DataDirectory|aspnetdb.mdf�. The string |DataDirectory|� is translated
at runtime to point to the
~/App_Data/ directory, so the database path
|DataDirectory|aspnetdb.mdf" translates to
If we did not specify any Membership provider information in our application's
Web.config file, the application uses the default registered Membership
AspNetSqlMembershipProvider. If the
database does not exist, the ASP.NET runtime will automatically create it and add
the application services schema. However, we don't want to use the
database; rather, we want to use the
we created in Step 2. This modification can be accomplished in one of two ways:
- Specify a value for the
LocalSqlServerconnection string name in
Web.config. By overwriting the
LocalSqlServerconnection string name value in
Web.config, we can use the default registered Membership provider (
AspNetSqlMembershipProvider) and have it correctly work with the
SecurityTutorials.mdfdatabase. This approach is fine if you are content with the configuration settings specified by
AspNetSqlMembershipProvider. For more information on this technique, see Scott Guthrie's blog post, Configuring ASP.NET 2.0 Application Services to Use SQL Server 2000 or SQL Server 2005.
- Add a new registered provider of type
SqlMembershipProviderand configure its
connectionStringNamesetting to point to the
SecurityTutorials.mdfdatabase. This approach is useful in scenarios where you want to customize other configuration properties in addition to the database connection string. In my own projects I always use this approach because of its flexibility and readability.
Before we can add a new registered provider that references the
database, we first need to add an appropriate connection string value in the
Web.config. The following markup adds a new connection string
SecurityTutorialsConnectionString that references the SQL Server
2005 Express Edition
SecurityTutorials.mdf database in the
connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\SecurityTutorials.mdf;Integrated Security=True;User Instance=True"
... Configuration markup removed for brevity ...
Note: If you are using an alternate database file, update the connection string as needed. For more information on forming the correct connection string, refer to ConnectionStrings.com.
Next, add the following Membership configuration markup to the
file. This markup registers a new provider named
connectionString="Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\SecurityTutorials.mdf;Integrated Security=True;User Instance=True"
<!--Add a customized SqlMembershipProvider -->
... Configuration markup removed for brevity ...
In addition to registering the
provider, the above markup defines the
as the default provider (via the
defaultProvider attribute in the
<membership> element). Recall that the Membership framework can
have multiple registered providers. Since
is registered as the first provider in
machine.config, it serves as
the default provider unless we indicate otherwise.
Currently, our application has two registered providers:
SecurityTutorialsSqlMembershipProvider. However, before registering
SecurityTutorialsSqlMembershipProvider provider we could have cleared
out all previously registered providers by adding a
<clear /> element immediately before our
element. This would clear out the
the list of registered providers, meaning that the
would be the only registered Membership provider. If we used this approach, then
we would not need to mark the
as the default provider, since it would be the only registered Membership provider.
For more information on using
<clear />, see
<clear /> When Adding Providers.
Note that the
setting references the just-added
connection string name, and that its
applicationName setting has been
set to a value of SecurityTutorials . Additionally, the
setting has been set to
true. All other configuration options are identical
to the values in
AspNetSqlMembershipProvider. Feel free to make any
configuration modifications here, if you wish. For example, you could tighten the
password strength by requiring two non-alphanumeric characters instead of one, or
by increasing the password length to eight characters instead of seven.
Note: Recall that the Membership framework allows for a single user store
to be partitioned across multiple applications. The Membership provider's
setting indicates what application the provider uses when working with the user
store. It is important that you explicitly set a value for the
configuration setting because if the
applicationName is not explicitly
set, it is assigned to the web application's virtual root path at runtime. This
works fine as long as the application's virtual root path doesn't change, but if
you move the application to a different path, the
will change too. When this happens, the Membership provider will start working with
a different application partition than was previously used. User accounts created
prior to the move will reside in a different application partition and those users
will no longer be able to log into the site. For a more in-depth discussion on this
Always Set the
applicationName Property When Configuring ASP.NET 2.0
Membership and Other Providers.
At this point we have a database with the configured application services (
and have configured our web application so that the Membership framework uses the
SecurityTutorialsSqlMembershipProvider provider we just registered.
This registered provider is of type
SqlMembershipProvider and has its
connectionStringName set to the appropriate connection string (
applicationName value explicitly set.
We are now ready to use the Membership framework from our application. In the next tutorial we will examine how to create new user accounts. Following that we will explore authenticating users, performing user-based authorization, and storing additional user-related information in the database.
For more information on the topics discussed in this tutorial, refer to the following resources:
Always Set the
applicationNameProperty When Configuring ASP.NET 2.0 Membership and Other Providers
- Configuring ASP.NET 2.0 Application Services to Use SQL Server 2000 or SQL Server 2005
- Download SQL Server Management Studio Express Edition
- Examining ASP.NET 2.0�s Membership, Roles, and Profile
<add>Element for Providers for Membership
<providers>Element for Membership
<clear />When Adding Providers
- Working Directly
Video Training on Topics Contained in this Tutorial
- Understanding ASP.NET Memberships
- Configuring SQL To Work with Membership Schemas
- Changing Membership Settings in the Default Membership Schema
About the Author
Scott Mitchell, author of multiple ASP/ASP.NET books and founder of 4GuysFromRolla.com, has been working with Microsoft Web technologies since 1998. Scott works as an independent consultant, trainer, and writer. His latest book is Sams Teach Yourself ASP.NET 2.0 in 24 Hours. Scott can be reached at email@example.com or via his blog at http://ScottOnWriting.NET.
Special Thanks To
This tutorial series was reviewed by many helpful reviewers. Lead reviewer for this tutorial was Alicja Maziarz. Interested in reviewing my upcoming MSDN articles? If so, drop me a line at mitchell@4GuysFromRolla.com.