Types

SQLite Types

SQLDelight column definitions are identical to regular SQLite column definitions but support an extra column constraint which specifies the Kotlin type of the column in the generated interface. SQLDelight natively supports Long, Double, String, ByteArray, Int, Short, Float, and Booleans.

CREATE TABLE some_types (
  some_long INTEGER,           -- Stored as INTEGER in db, retrieved as Long
  some_double REAL,            -- Stored as REAL in db, retrieved as Double
  some_string TEXT,            -- Stored as TEXT in db, retrieved as String
  some_blob BLOB,              -- Stored as BLOB in db, retrieved as ByteArray
  some_int INTEGER AS Int,     -- Stored as INTEGER in db, retrieved as Int
  some_short INTEGER AS Short, -- Stored as INTEGER in db, retrieved as Short
  some_float REAL AS Float     -- Stored as REAL in db, retrieved as Float
);

Boolean columns are stored in the db as INTEGER, and so they can be given INTEGER column constraints. Use DEFAULT 0 to default to false, for example.

CREATE TABLE hockey_player (
  injured INTEGER AS Boolean DEFAULT 0
)

Custom Column Types

If you'd like to retrieve columns as custom types you can specify a Kotlin type:

import kotlin.collections.List;

CREATE TABLE hockeyPlayer (
  cup_wins TEXT AS List<String> NOT NULL
);

However, creating the Database will require you to provide a ColumnAdapter which knows how to map between the database type and your custom type:

val listOfStringsAdapter = object : ColumnAdapter<List<String>, String> {
  override fun decode(databaseValue: String) =
    if (databaseValue.isEmpty()) {
      listOf()
    } else {
      databaseValue.split(",")
    }
  override fun encode(value: List<String>) = value.joinToString(separator = ",")
}

val queryWrapper: Database = Database(
  driver = driver,
  hockeyPlayerAdapter = hockeyPlayer.Adapter(
    cup_winsAdapter = listOfStringsAdapter
  )
)

Enums

As a convenience the SQLDelight runtime includes a ColumnAdapter for storing an enum as String data.

import com.example.hockey.HockeyPlayer;

CREATE TABLE hockeyPlayer (
  position TEXT AS HockeyPlayer.Position
)

val queryWrapper: Database = Database(
  driver = driver,
  hockeyPlayerAdapter = HockeyPlayer.Adapter(
    positionAdapter = EnumColumnAdapter()
  )
)