Yes, you can prevent SQL injection in .NET C#. Here are some of the best practices to prevent SQL injection in .NET C#:

• Use parametrized queries. Parametrized queries are a secure way to pass user input to a database. When you use parametrized queries, the user input is not embedded in the SQL query itself. Instead, the user input is passed to the database as a parameter. This prevents attackers from injecting malicious code into the SQL query.
• Use ORMs. Object-relational mappers (ORMs) are a great way to prevent SQL injection. ORMs abstract the database layer from the application layer. This means that you don't have to write raw SQL queries. Instead, you can use the ORM to create and execute queries. The ORM will automatically take care of parameterizing the queries and preventing SQL injection.
• Validate user input. Even if you use parametrized queries or ORMs, you should still validate user input. This will help to prevent attackers from injecting malicious code into the application. You should validate user input for length, format, and content.
• Use a web application firewall (WAF). A WAF is a security appliance that can help to protect your application from SQL injection attacks. A WAF can filter out malicious traffic and prevent attackers from injecting malicious code into your application.

By following these best practices, you can help to prevent SQL injection in your .NET C# applications.

Here are some additional tips to prevent SQL injection in .NET C#:

• Use prepared statements instead of dynamic SQL. Prepared statements are pre-compiled SQL statements that are stored in the database. When you use prepared statements, the database will bind the user input to the parameters in the statement. This prevents attackers from injecting malicious code into the statement.
• Escape user input. When you need to use user input in a string, you should escape the input. This will prevent attackers from injecting malicious code into the string.
• Use the least privilege principle. Give database users only the permissions that they need to perform their job. This will help to prevent attackers from exploiting vulnerabilities in the database.
• Keep your software up to date. Software vendors often release security patches to fix vulnerabilities. Make sure that you install security patches as soon as they are released.

By following these tips, you can help to prevent SQL injection in your .NET C# applications.