Connection to a database
To connect to a database, DataGrip requires connection details (for example, host, port, password, SSH configuration settings, and so on). For every database, the connection details are stored in a dedicated connection configuration — data source.
For a data source, connections to the database are established in special wrappers — sessions. Each session is a wrapper over a single connection, and it stores the connection's information (for example, whether it is active or not, transaction control mode, and other settings).
Sessions can have clients — files, whose queries are sent via the connection that the session holds. Data editor can also be a client for a session.
Depending on the way you create a new session, it can be connected either automatically, or after a certain action. Green dot in the corner of session's icon indicates the connected status.
You can create a new session by doing either of the following:
Open a query console or view database object's data in data editor.
As a result, under the data source node in the Services tool window, the new session node appears with a client node under it.
For a query console, the session will be connected once you perform an action that requires interaction with the database. For example, once you run a query.
For a table, the session is connected automatically, as DataGrip requires an active connection to request the table data from the database, receive it, and display it in the data editor.
As a result, the new connected session node appears under the data source node in the Services tool window.