Android Room级联删除一对多关系

Question

假设我有两个实体，锻炼和锻炼，锻炼(一个)和锻炼(许多)之间存在一对多的关系。实体是这样设置的

锻炼实体:

@Entity(
    tableName = "workouts",
    indices = [Index("startDate")]
)
data class Workout(
    @PrimaryKey
    val startDate: String,

    val workoutName: String
)

行使实体:

@Entity
data class Exercise(
    @PrimaryKey(autoGenerate = true)
    val exerciseId: Long = 0,

    val workoutId: String,

    val name: String
)

锻炼锻炼:

@Entity(
    foreignKeys = [ForeignKey(
        entity = Workout::class,
        parentColumns = arrayOf("startDate"),
        childColumns = arrayOf("workoutId"),
        onDelete = ForeignKey.CASCADE
    )]
)
data class Exercise(
    @PrimaryKey(autoGenerate = true)
    val exerciseId: Long = 0,

    val workoutId: String,

    val name: String
)

这就是我获得与锻炼相关的练习的方式:

@Transaction
@Query("SELECT * FROM workouts WHERE startDate = :startDate")
suspend fun getWorkoutWithExercises(startDate: String): WorkoutWithExercises

所以我的问题是，如果包含练习的锻炼实例被删除，相关的练习也会被删除吗？如果没有，这将如何实现？

谢谢

Answer 1

当您创建了 Foreign Key 时，这些练习也将被删除。为表练习。