DatabaseView
@Target(allowedTargets = [AnnotationTarget.CLASS])
@Retention(value = AnnotationRetention.BINARY)
public annotation DatabaseView
Marks a class as an SQLite view.
The value of the annotation is a SELECT query used when the view is created.
The class will behave like normal POJO when it is used in a Dao. You can SELECT FROM a DatabaseView similar to an Entity, but you can not INSERT, DELETE or UPDATE into a DatabaseView.
Similar to an Entity, you can use ColumnInfo and Embedded inside to customize the data class.
Example:
@DatabaseView(
"SELECT id, name, release_year FROM Song " +
"WHERE release_year >= 1990 AND release_year <= 1999"
)
data class SongFrom90s (
val id: Long,
val name: String,
@ColumnInfo(name = "release_year")
val releaseYear: Int
)
Views have to be registered to a RoomDatabase via Database.views.
| See also | |
|---|---|
Dao |
|
Database |
|
ColumnInfo |
|
Embedded |
Summary
Public constructors |
|---|
DatabaseView(@NonNull String value, @NonNull String viewName) |
Public methods |
|
|---|---|
final @NonNull String |
getValue()The SELECT query. |
final @NonNull String |
The view name in the SQLite database. |
Public constructors
Public methods
getViewName
public final @NonNull String getViewName()
The view name in the SQLite database. If not set, it defaults to the class name.