Java android 房间二外键

Question

我有一个 table 有两个外键分成两个不同的 tables

这是我的 table :

@Entity(
        tableName = Constants.TABLE_NAME_PICTURE,
        foreignKeys = {
        @ForeignKey(
                entity = BIN.class,
                parentColumns = "id",
                childColumns = "bin_id"
        ),
        @ForeignKey(
                entity = ORDER.class,
                parentColumns = "id",
                childColumns = "order_id"
        )},
        indices = {@Index("id"), @Index(value = {"bin_id","order_id"})})

public class PICTURE {

    @PrimaryKey(autoGenerate = true)
    @ColumnInfo(name = "id")
    public long id;
    @Attribute(name = "name", required = false)
    @ColumnInfo(name = "name")
    public String name;
    @ColumnInfo(name = "bin_id")
    public int binId;
    @ColumnInfo(name = "order_id")
    public int orderId;

当我将图片插入数据库时，我得到：

android.database.sqlite.SQLiteConstraintException: FOREIGN KEY constraint failed (code 787)

Answer 1

我认为你必须更改此行

foreignKeys = {
    @ForeignKey(
            entity = BIN.class,
            parentColumns = {"id"},
            childColumns = {"bin_id"}
    ),
    @ForeignKey(
            entity = ORDER.class,
            parentColumns = {"id"}
            childColumns = {"order_id"}
    )},

Answer 2

您似乎没有添加任何第二行 table，如 BIN.class 和 Order.class。我从

那里得到了答案

Answer 3

试着这样做

foreignKeys = [
        @ForeignKey(
                entity = BIN.class,
                parentColumns = "id",
                childColumns = "bin_id"
        ),
        @ForeignKey(
                entity = ORDER.class,
                parentColumns = "id",
                childColumns = "order_id"
        )],

其实在kotlin中我是这样写这一行的

foreignKeys = arrayOf(
            @ForeignKey(
                    entity = BIN.class,
                    parentColumns = "id",
                    childColumns = "bin_id"
            ),
            @ForeignKey(
                    entity = ORDER.class,
                    parentColumns = "id",
                    childColumns = "order_id"
            )]),

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