Greetings Dev! In the world of databases, security is of utmost importance. When it comes to SQL Server, authentication is a crucial component of that security. In this article, we will dive deep into SQL Server authentication and cover all the important aspects. So, without further ado, let’s get started!
What is SQL Server Authentication?
SQL Server authentication is the process of verifying the identity of a user who wants to access a SQL Server instance. In simple terms, it is the way of ensuring that only authorized users can access the database. There are two types of SQL Server authentication: Windows authentication and SQL Server authentication.
Windows Authentication
With Windows authentication, the user’s Windows credentials are used to authenticate the user. This means that the user needs to have a Windows account and needs to be added as a login to the SQL Server instance. When the user tries to access the database, SQL Server verifies their Windows credentials, and if they are valid, grants them access.
Windows authentication is considered more secure than SQL Server authentication because it is based on the user’s Windows account, which is managed by the Windows domain. Windows accounts are also subject to password policies set by the domain, which makes them more secure.
SQL Server Authentication
With SQL Server authentication, the user provides a login name and password to authenticate. The login and password are stored in SQL Server, and when the user tries to access the database, SQL Server verifies the login name and password. If they are valid, access is granted.
SQL Server authentication is useful when the user does not have a Windows account, or when the user needs to connect to the SQL Server instance from a non-Windows platform, like Linux or macOS.
SQL Server Authentication Modes
SQL Server supports two authentication modes: Windows Authentication Mode and Mixed Mode.
Windows Authentication Mode
Windows Authentication Mode is the default authentication mode for SQL Server. When the SQL Server is installed, it is configured to use Windows Authentication Mode. In this mode, only Windows accounts can connect to the SQL Server instance.
Mixed Mode
Mixed Mode is the other authentication mode supported by SQL Server. In this mode, both Windows authentication and SQL Server authentication are allowed. The user can choose which authentication method to use when connecting to the SQL Server instance.
Mixed Mode is useful when there are users who do not have Windows accounts or when users need to connect to the SQL Server instance from a non-Windows platform.
Creating Logins
In SQL Server, a login is required to access the instance. A login can be created using Transact-SQL statements or SQL Server Management Studio.
Creating a Login using Transact-SQL
The following Transact-SQL statement creates a login:
Command |
Description |
|---|---|
CREATE LOGIN login_name |
Creates a login with the specified name. |
WITH PASSWORD = ‘password’ |
Specifies the password for the login. |
For example, the following statement creates a login named ‘devuser’ with the password ‘abc123’:
Command |
Description |
|---|---|
CREATE LOGIN devuser |
Creates a login with the name ‘devuser’. |
WITH PASSWORD = ‘abc123’ |
Specifies the password ‘abc123’ for the login. |
Creating a Login using SQL Server Management Studio
To create a login using SQL Server Management Studio, follow these steps:
- Open SQL Server Management Studio.
- Connect to the SQL Server instance.
- Expand the Security folder.
- Right-click on Logins and select New Login.
- In the Login – New dialog box, enter the login name.
- Select SQL Server Authentication.
- Enter the password for the login.
- Select the default database for the login.
- Click OK.
Assigning Server Roles
Server roles are a way of grouping server-level permissions together. There are several built-in server roles in SQL Server, like sysadmin, dbcreator, and securityadmin. Server roles can be assigned to logins using Transact-SQL statements or SQL Server Management Studio.
Assigning Server Roles using Transact-SQL
The following Transact-SQL statement assigns the sysadmin server role to a login:
Command |
Description |
|---|---|
ALTER SERVER ROLE sysadmin ADD MEMBER login_name |
Adds the login to the sysadmin server role. |
For example, the following statement adds the login ‘devuser’ to the sysadmin server role:
Command |
Description |
|---|---|
ALTER SERVER ROLE sysadmin ADD MEMBER devuser |
Adds the login ‘devuser’ to the sysadmin server role. |
Assigning Server Roles using SQL Server Management Studio
To assign server roles using SQL Server Management Studio, follow these steps:
- Open SQL Server Management Studio.
- Connect to the SQL Server instance.
- Expand the Security folder.
- Right-click on Server Roles and select New Server Role.
- In the New Server Role dialog box, enter the name of the server role.
- Select the server-level permissions that should be included in the server role.
- Click OK.
- Right-click on the server role and select Properties.
- In the Server Role Properties dialog box, select Members.
- Click Add.
- Select the login that should be added to the server role.
- Click OK.
- Click OK again to close the Server Role Properties dialog box.
FAQ
What is the difference between Windows authentication and SQL Server authentication?
With Windows authentication, the user’s Windows credentials are used to authenticate the user. With SQL Server authentication, the user provides a login name and password to authenticate. Windows authentication is considered more secure than SQL Server authentication because it is based on the user’s Windows account, which is managed by the Windows domain.
What is Mixed Mode Authentication in SQL Server?
Mixed Mode Authentication is the authentication mode in SQL Server that allows both Windows authentication and SQL Server authentication.
How do I create a login in SQL Server using SQL Server Management Studio?
To create a login using SQL Server Management Studio, follow these steps:
- Open SQL Server Management Studio.
- Connect to the SQL Server instance.
- Expand the Security folder.
- Right-click on Logins and select New Login.
- In the Login – New dialog box, enter the login name.
- Select SQL Server Authentication.
- Enter the password for the login.
- Select the default database for the login.
- Click OK.
How do I assign server roles in SQL Server using Transact-SQL?
To assign a server role to a login using Transact-SQL, use the following statement:
Command |
Description |
|---|---|
ALTER SERVER ROLE server_role_name ADD MEMBER login_name |
Adds the login to the specified server role. |
How do I assign server roles in SQL Server using SQL Server Management Studio?
To assign server roles using SQL Server Management Studio, follow these steps:
- Open SQL Server Management Studio.
- Connect to the SQL Server instance.
- Expand the Security folder.
- Right-click on Server Roles and select New Server Role.
- In the New Server Role dialog box, enter the name of the server role.
- Select the server-level permissions that should be included in the server role.
- Click OK.
- Right-click on the server role and select Properties.
- In the Server Role Properties dialog box, select Members.
- Click Add.
- Select the login that should be added to the server role.
- Click OK.
- Click OK again to close the Server Role Properties dialog box.
That’s all for now, Dev! We hope this article has provided you with a thorough understanding of SQL Server authentication. If you have any questions or comments, feel free to leave them below.