DBFlow
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Main Usage
DBFlow supports a number of database features that will enhance and decrease time you need to spend coding with databases. We support multiple databases at the same time (and in separate modules) as long as there's no shared models.
What is covered in these docs are not all inclusive, but should give you an idea of how to operate with DBFlow on databases.
There are a few concepts to familiarize yourself with. We will go more in depth in other sections in this doc.
SQLite Wrapper Language: DBFlow provides a number of convenience methods, extensions, and generated helpers that produce a concise, flowable query syntax. A few examples below:
List<User> users = SQLite.select()
.from(User.class)
.where(name.is("Andrew Grosner"))
.queryList();
SQLite.update(User.class)
.set(name.eq("Andrew Grosner"))
.where(name.eq("Andy Grosner"))
.executeUpdateDelete()
FlowManager.getDatabase(AppDatabase.class).beginTransactionAsync((DatabaseWrapper wrapper) -> {
// wraps in a SQLite transaction, do something on BG thread.
});
CursorResult<User> results = SQLite.select().from(User.class).queryResults();
try {
for (User user: results) { // memory efficient iterator
}
} finally {
results.close()
}
Or in Kotlin:
val users = (select from User::class where (name `is` "Andrew Grosner")).list
(update<User>() set (name eq "Andrew Grosner") where (name eq "Andy Grosner")).executeUpdateDelete()
database<AppDatabase>().beginTransactionAsync {
}
(select from User::class).queryResults().use { results ->
for (user in results) {
}
}
Caching: DBFlow supports caching in models. Caching them greatly increases speed, but cache carefully as it can lead to problems such as stale data.
@Table(cachingEnabled = true)
public class User
Migrations: Migrations are made very simple in DBFlow. We only support the kinds that SQLite provide, but also allow you to modify the data within the DB in a structured way during these. They are also run whenever the SQLiteOpenHelper detects a version change in the order of version they specify.
Multiple Modules: DBFlow can be used in library projects, in any number of inner-project modules simultaneously. However these models must reside in separate databases.
Relationships: Not the human kind. We support @ForeignKey including multiple foreign keys for 1-1. @OneToMany is a manual relationship generated by the compiler between two tables to manage data.@ManyToMany generates a join table between two tables for many to many relationships.
Views: Declared like tables, Views (Virtual Tables) are supported.
Query Models: Query models have no SQLite connection, but are extremely useful for custom queries or join queries that return a result set not mappable to any model you currently use for tables.
Encrypted Databases: DBFlow supports database encryption for security using SQLCipher through a separate, easy-to-integrate artifact.
Indexes: A SQLite feature that drastically improves query performance on large datasets. Dead-easy to implement.
Reactive: Easily listen to changes in database data via ModelNotifier system.
Transaction Management: Place all transactions and retrievals on same background thread for maximum efficiency and to prevent UI-hiccups.
Type Converters: Have custom data? Define a TypeConverter to map it to SQLite data types.
Last modified 3yr ago
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