Rack.java

@Entity(tableName = "rack_table")
@ForeignKey(
        entity = Storage.class,
        parentColumns = "storage_id",
        childColumns = "rack_id",
        onDelete = ForeignKey.CASCADE,
        onUpdate = ForeignKey.CASCADE
)

public class Rack
{
    @PrimaryKey(autoGenerate = true)
    @ColumnInfo(name = "rack_id")
    public long rackID;

    @ColumnInfo(name = "storage_id")
    public long storageID;
        /// ....