Connect to SQL Server Express LocalDB

To connect to your LocalDB instance with JetBrains Rider, check if your LocalDB instance is ready for a connection. To do that, locate SqllocalDB.exe and run the following command in a command prompt:
You will see a list of available LocalDB instances on the server.
SqllocalDB.exe i
Next, create a LocalDB instance. To create an instance, run the following command:
SqlLocalDB create "DEVELOPMENT" 15.0 -s
This command creates an instance of LocalDB named DEVELOPMENT by using SQL Server 2017 binaries and starts the instance. If you omit 15.0, the version number defaults to the version of the SqlLocalDB utility.
To check an instance state, run this command.
SqllocalDB.exe i MSSQLLocalDB
Currently, the instance is running (see the State field). If you have the Stopped state, start the instance by running the following command in the terminal.
SqllocalDB.exe s MSSQLLocalDB
By default, every LocalDB instance is stopped after several minutes of inactivity. You can change this behavior by changing user instance timeout option with T-SQL (read more at stackoverflow.com). Since JetBrains Rider 2019.2, when IDE connects to LocalDB, the LocalDB instance is started automatically.

In the Database tool window (View | Tool Windows | Database), click the Data Source Properties icon .
From the Driver list, select Microsoft SQL Server (jTds).
At the bottom of the data source settings area, click the Download missing driver files link. As you click this link, JetBrains Rider downloads drivers that are required to interact with a database. To decrease the size of the installation package and keep driver versions up-to-date, drivers are not bundled with the IDE.
You can specify your own drivers for the data source if you do not want to download the provided drivers. For more information about creating a database connection with your driver, see Add a user driver to an existing connection.
From the Connection type list, select LocalDB.
From the Instance list, select the instance to connect to (for example, DEVELOPMENT).
From the Authentication list, select the authentication type:
- User & Password requires a username and a password.
- Windows credentials requires you to run JetBrains Rider on Windows in the same domain as the Microsoft SQL Server database. Works as the Single-Sign On (SSO).
- Domain credentials requires a domain, a username, and a password.
To ensure that the connection to the data source is successful, click the Test Connection link.

Last modified: 27 March 2021