DatabaseRegionConvertible

A DatabaseRegionConvertible instance feeds database observation tools such as DatabaseRegionObservation and ValueObservation:

// An observation triggered by all changes to the database
DatabaseRegionObservation(tracking: .fullDatabase)

// An observation triggered by all changes to the 'player' table
DatabaseRegionObservation(tracking: Table("player"))

// An observation triggered by all changes to the row
// with rowid 1 in the 'player' table
DatabaseRegionObservation(tracking: Player.filter(id: 1))

// An observation triggered by all changes to the 'score' column
// of the 'player' table
DatabaseRegionObservation(tracking: SQLRequest("SELECT score FROM player"))

Specifying a region from a FetchRequest does not execute the request. In the above example, Player.filter(id: 1) and SELECT score FROM player are only compiled by SQLite, so that GRDB can understand the tables, rows, and columns that constitute the database region.

Creating a DatabaseRegion

• static var fullDatabase: Self

  The region that covers the full database: all columns and all rows from all tables.

• func databaseRegion(Database) throws -> DatabaseRegion

  Returns a database region.

Supporting Types

• struct AnyDatabaseRegionConvertible

  A type-erased DatabaseRegionConvertible