Dynamically change entity frame connections at runtime

In a Web API project, the ability to change the data context connection based on user input is usually necessary. In this case, the connection string must be dynamic and adjustable.

To build the connection string, SqlConnectionStringBuilder and EntityConnectionStringBuilder] are used. SqlConnectionStringBuilder configures SQL connection parameters, while EntityConnectionStringBuilder sets entity framework connection details.

Modify data context connection

To change the data context connection, you can use an extension method called ChangeDatabase. This method accepts optional parameters that specify the new database details and connection string name if it is different from the base EF class name.

Inside the ChangeDatabase method, the EntityConnectionStringBuilder is initialized with an existing connection string. Then, create a SqlConnectionStringBuilder and fill it with the specified parameters. Finally, the modified connection string is set to the data context connection string.

Connection string persistence

In a Web API project, the connection string is usually set during user login and should persist during user interaction. For persistence, connection strings can be stored in session variables, application-level caches, or persistence repositories.

By using the ChangeDatabase extension method and implementing connection string persistence, you can dynamically change entity framework connections at runtime based on user selection.