Getting Started with SQLite on Android¶
First apply the gradle plugin in your project.
plugins {
id("app.cash.sqldelight") version "2.0.2"
}
repositories {
google()
mavenCentral()
}
sqldelight {
databases {
create("Database") {
packageName.set("com.example")
}
}
}
plugins {
id "app.cash.sqldelight" version "2.0.2"
}
repositories {
google()
mavenCentral()
}
sqldelight {
databases {
Database { // This will be the name of the generated database class.
packageName = "com.example"
}
}
}
Tip
It's recommended to switch Android Studio to use the "Project" view instead of the "Android" view of your files, to make it easier to find and edit SQLDelight files.
Defining the Schema¶
Write your SQL statements in a .sq
file under src/main/sqldelight
.
Typically the first statement in the .sq
file creates a table, but you can also create indexes
or set up default content.
CREATE TABLE hockeyPlayer (
player_number INTEGER PRIMARY KEY NOT NULL,
full_name TEXT NOT NULL
);
CREATE INDEX hockeyPlayer_full_name ON hockeyPlayer(full_name);
INSERT INTO hockeyPlayer (player_number, full_name)
VALUES (15, 'Ryan Getzlaf');
From these statements, SQLDelight will generate a Database
class with an associated Schema
object that can be used to create your database and execute statements on it. The Database
class
is generated by the generateSqlDelightInterface
Gradle task which is run automatically by the
SQLDelight IDE plugin when you edit a .sq
file, and also as part of a normal Gradle build.
To use the generated database in your code, you must add the SQLDelight Android driver dependency to your project.
dependencies {
implementation("app.cash.sqldelight:android-driver:2.0.2")
}
dependencies {
implementation "app.cash.sqldelight:android-driver:2.0.2"
}
An instance of the driver can be constructed as shown below, and requires a reference to the generated Schema
object.
val driver: SqlDriver = AndroidSqliteDriver(Database.Schema, context, "test.db")
Info
The AndroidSqliteDriver
will automatically create or migrate your schema when the driver is constructed.
Migrations can also be executed manually if needed. See Code Migrations for more
Defining Typesafe Queries¶
SQLDelight will generate a typesafe function for any labeled SQL statement in a .sq
file.
selectAll:
SELECT *
FROM hockeyPlayer;
insert:
INSERT INTO hockeyPlayer(player_number, full_name)
VALUES (?, ?);
insertFullPlayerObject:
INSERT INTO hockeyPlayer(player_number, full_name)
VALUES ?;
A "Queries" object will be generated for each .sq
file containing labeled statements.
For example, a PlayerQueries
object will be generated for the Player.sq
file shown above.
This object can be used to call the generated typesafe functions which will execute the actual SQL
statements.
fun doDatabaseThings(driver: SqlDriver) {
val database = Database(driver)
val playerQueries: PlayerQueries = database.playerQueries
println(playerQueries.selectAll().executeAsList())
// [HockeyPlayer(15, "Ryan Getzlaf")]
playerQueries.insert(player_number = 10, full_name = "Corey Perry")
println(playerQueries.selectAll().executeAsList())
// [HockeyPlayer(15, "Ryan Getzlaf"), HockeyPlayer(10, "Corey Perry")]
val player = HockeyPlayer(10, "Ronald McDonald")
playerQueries.insertFullPlayerObject(player)
}
And that's it! Check out the other pages on the sidebar for other functionality.
SQLite Versions¶
For Android projects, the SQLDelight Gradle plugin will automatically select the SQLite dialect
version based on your project's minSdkVersion
setting. See here for
the list of supported SQLite versions on each Android SDK level.