如果有一种方法可以在我的连接表中添加额外的信息，那就太好了。
有一种方法，您只需（根据结果）将该表视为普通表并从中检索数据。
所以你可以有这样的东西：

data class JobPW(
    @Embedded val job: Job,
    @Relation(
        parentColumn = "job_id",
        entityColumn = "worker_id",
        associateBy = Junction(JobWorkerCrossRef::class)
    )
    /*<<<<<<<<<< ADDDED >>>>>>>>>>*/
    val workers: List<Worker> ,
    @Relation(
        entity = JobWorkerCrossRef::class,
        entityColumn = "job_id",
        parentColumn = "job_id"
    )
    val junctionWithExtra: List<JobWorkerCrossRef>,
    (<<<<<<<<<< END OF ADDITION >>>>>>>>>*/
    @Relation(
        entity = Poster::class,
        parentColumn = "job_id",
        entityColumn = "job_id_map"
    )
    val posters: List<PosterWithWorker>
) : Serializable

工作示例

下面是一个工作示例，基于问题中的代码，添加了省略的类来科普（为了演示的简洁，适合在没有流/挂起的主线程上运行）。因此，演示的整个数据库代码是：

@Entity
data class Owner(
    @PrimaryKey
    val owner_id: Long?=null,
    val ownerName: String
)

@Entity
data class Poster(
    @PrimaryKey
    val poster_id: Long?=null,
    @ColumnInfo(index = true)
    val job_id_map: Long,
    val worker_id: Long,
    val posterName: String
)

@Entity(
    foreignKeys = [
        ForeignKey(
            entity = Owner::class,
            parentColumns = ["owner_id"],
            childColumns = ["owner_id_map"],
            onDelete = ForeignKey.CASCADE,
            onUpdate = ForeignKey.CASCADE
        )
    ]
)
data class Job (
    @PrimaryKey val job_id: Long?=null,
    val status: Int,
    @ColumnInfo(index = true)
    val owner_id_map: Long,
    val title: String,
    val city: String
) : Serializable

data class JobPW(
    @Embedded val job: Job,
    @Relation(
        parentColumn = "job_id",
        entityColumn = "worker_id",
        associateBy = Junction(JobWorkerCrossRef::class)
    )
    val workers: List<Worker> ,
    @Relation(
        entity = JobWorkerCrossRef::class,
        entityColumn = "job_id",
        parentColumn = "job_id"
    )
    val junctionWithExtra: List<JobWorkerCrossRef>,

    @Relation(
        entity = Poster::class,
        parentColumn = "job_id",
        entityColumn = "job_id_map"
    )
    val posters: List<PosterWithWorker>
) : Serializable

@Entity
data class Worker(
    @PrimaryKey
    @ColumnInfo(name = "worker_id")
    val worker_id: Long?=null,
    val workerName: String
) : Serializable

data class PosterWithWorker(
    @Embedded
    val poster: Poster,
    @Relation(
        entity = Worker::class,
        entityColumn = "worker_id",
        parentColumn = "poster_id"
    )
    val workers: List<Worker>
)

@Entity(
    primaryKeys = ["job_id","worker_id"], /* composite primary key */
    foreignKeys = [
        ForeignKey(
            entity = Job::class,
            parentColumns = ["job_id"],
            childColumns = ["job_id"],
            onDelete = ForeignKey.CASCADE,
            onUpdate = ForeignKey.CASCADE
        ),
        ForeignKey(
            entity = Worker::class,
            parentColumns = ["worker_id"],
            childColumns = ["worker_id"],
            onDelete = ForeignKey.CASCADE,
            onUpdate = ForeignKey.CASCADE
        )
    ]
)
data class JobWorkerCrossRef(
    val job_id: Long,
    @ColumnInfo(index = true)
    val worker_id: Long,
    val extraData: String
)

@Dao
interface AllDAOs {

    @Insert(onConflict = OnConflictStrategy.IGNORE)
    fun insert(owner: Owner): Long
    @Insert(onConflict = OnConflictStrategy.IGNORE)
    fun insert(worker: Worker): Long
    @Insert(onConflict = OnConflictStrategy.IGNORE)
    fun insert(poster: Poster): Long
    @Insert(onConflict = OnConflictStrategy.IGNORE)
    fun insert(job: Job): Long
    @Insert(onConflict = OnConflictStrategy.IGNORE)
    fun insert(jobWorkerCrossRef: JobWorkerCrossRef): Long

    @Transaction
    @Query("SELECT * FROM job")
    /*suspend*/ fun getJobs(): List<JobPW>

}

@Database(entities = [Owner::class,Job::class,Poster::class,Worker::class,JobWorkerCrossRef::class], exportSchema = false, version = 1)
abstract class TheDatabase: RoomDatabase() {
    abstract fun getAllDAOs(): AllDAOs

    companion object {
        private var instance: TheDatabase?=null
        fun getInstance(context: Context): TheDatabase {
            if (instance==null) {
                instance=Room.databaseBuilder(context,TheDatabase::class.java,"the_database.db")
                    .allowMainThreadQueries()
                    .build()
            }
            return instance as TheDatabase
        }
    }
}

• 显然，由于问题中的代码遗漏，会有差异，因此您必须调整代码以应用所使用的原则。

为了演示在活动中使用了以下代码。该代码加载了一些数据（仅用于单次运行，而不是重复运行），然后使用修改后的JobPW POJO从问题中提取数据（请注意，这只是为了获得额外的数据而修改的）：-

class MainActivity : AppCompatActivity() {
    lateinit var db: TheDatabase
    lateinit var dao: AllDAOs
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        db = TheDatabase.getInstance(this)
        dao = db.getAllDAOs()

        val o1id = dao.insert(Owner(ownerName = "Owner1"))
        val o2id = dao.insert(Owner(ownerName = "Owner2"))
        val o3id = dao.insert(Owner(ownerName = "Owner3"))

        val j1id = dao.insert(Job(status = 1, owner_id_map = o1id, title = "Job1", city = "Somewhere"))
        val j2id = dao.insert(Job(status = 2, owner_id_map = o1id, title = "Job2", city = "Elsewhere"))
        val j3id = dao.insert(Job(status = 3, owner_id_map = o2id, title = "Job3", city = "Everywhere"))
        val j4id = dao.insert(Job(status = 4, owner_id_map = o3id, title = "Job4", city = "Nowhere"))

        val w1id = dao.insert(Worker(workerName = "Fred"))
        val w2id = dao.insert(Worker(workerName = "Mary"))
        val w3id = dao.insert(Worker(workerName = "Jane"))
        val w4id = dao.insert(Worker(workerName = "Tom"))
        val w5id = dao.insert(Worker(workerName = "Anne"))
        val w6id = dao.insert(Worker(workerName = "Bill"))

        val p1id = dao.insert(Poster(job_id_map = j1id, worker_id = w6id, posterName = "Poster1 for Job1 by Bill"))
        val p2id = dao.insert(Poster(job_id_map = j1id, worker_id = w5id, posterName = "Poster2 for Job1 by Anne"))
        val p3Id = dao.insert(Poster(job_id_map = j2id, worker_id = w6id, posterName = "Poster3 for Job2 by Bill"))
        val p4id = dao.insert(Poster(job_id_map = j3id, worker_id = w4id, posterName = "Poster4 for Job3 by Tom"))

        dao.insert(JobWorkerCrossRef(job_id = j1id, worker_id = w1id, extraData = "J1W1ABC"))
        dao.insert(JobWorkerCrossRef(job_id = j1id, worker_id = w3id, extraData = "J1W3DEF"))
        dao.insert(JobWorkerCrossRef(j1id,w5id,"J1W5GHI"))
        dao.insert(JobWorkerCrossRef(j2id,w2id,"J2W2JKL"))
        dao.insert(JobWorkerCrossRef(j2id   ,w4id,"J2W4MNO"))
        dao.insert(JobWorkerCrossRef(j2id,w6id,"J2W6PQR"))
        dao.insert(JobWorkerCrossRef(j4id,w1id,"J4W1STU"))
        dao.insert(JobWorkerCrossRef(j4id,w2id,"J4W2VWX"))
        dao.insert(JobWorkerCrossRef(j4id,w3id,"J4W3YZ1"))
        dao.insert(JobWorkerCrossRef(j4id,w4id,"J4W4234"))
        dao.insert(JobWorkerCrossRef(j4id,w5id,"J4W5567"))
        dao.insert(JobWorkerCrossRef(j4id,w6id,"J4W6890"))

        for(jpw in dao.getJobs()) {
            val pli = StringBuilder()
            for (p in jpw.posters) {
                val pwli = StringBuilder()
                for (w in p.workers) {
                    pwli.append("\n\n\tWorker is ${w.workerName} ID is ${w.worker_id} (via Poster)")
                }
                pli.append("\n\tPoster is ${p.poster.posterName} ID is ${p.poster.poster_id} mapped to JobID ${p.poster.job_id_map} there are ${p.workers.size} Workers. They are:-${pwli}")
            }
            val jpel = StringBuilder()
            for (je in jpw.junctionWithExtra) {
                jpel.append("\n\tJunctionWithExtra (Extra Data) is ${je.extraData} JobID is ${je.job_id} WorkerID is ${je.worker_id}")
            }
            val jwl = StringBuilder()
            for (w in jpw.workers) {
                jwl.append(("\n\tWorker is ${w.workerName} ID is ${w.worker_id} (via Job)"))
            }
            Log.d(
                "DBINFO",
                "Job is ${jpw.job.title} City is ${jpw.job.city} Status is ${jpw.job.status} JOBID is ${jpw.job.job_id} OwenerID is ${jpw.job.owner_id_map}" +
                        ".\nThere are ${jpw.posters}! They are:-$pli" +
                        ".\nThere are ${jpw.junctionWithExtra.size} Junctions With Extra Data! They are:-${jpel}" +
                        ".\nThere are ${jpw.workers.size} Workers!. They are:-${jwl}")
        }
    }
}

结果

2023-03-29 11:20:35.042 D/DBINFO: Job is Job1 City is Somewhere Status is 1 JOBID is 1 OwenerID is 1.
    There are [PosterWithWorker(poster=Poster(poster_id=1, job_id_map=1, worker_id=6, posterName=Poster1 for Job1 by Bill), workers=[Worker(worker_id=1, workerName=Fred)]), PosterWithWorker(poster=Poster(poster_id=2, job_id_map=1, worker_id=5, posterName=Poster2 for Job1 by Anne), workers=[Worker(worker_id=2, workerName=Mary)])]! They are:-
        Poster is Poster1 for Job1 by Bill ID is 1 mapped to JobID 1 there are 1 Workers. They are:-
    
        Worker is Fred ID is 1 (via Poster)
        Poster is Poster2 for Job1 by Anne ID is 2 mapped to JobID 1 there are 1 Workers. They are:-
    
        Worker is Mary ID is 2 (via Poster).
    There are 3 Junctions With Extra Data! They are:-
        JunctionWithExtra (Extra Data) is J1W1ABC JobID is 1 WorkerID is 1
        JunctionWithExtra (Extra Data) is J1W3DEF JobID is 1 WorkerID is 3
        JunctionWithExtra (Extra Data) is J1W5GHI JobID is 1 WorkerID is 5.
    There are 3 Workers!. They are:-
        Worker is Fred ID is 1 (via Job)
        Worker is Jane ID is 3 (via Job)
        Worker is Anne ID is 5 (via Job)
2023-03-29 11:20:35.042 D/DBINFO: Job is Job2 City is Elsewhere Status is 2 JOBID is 2 OwenerID is 1.
    There are [PosterWithWorker(poster=Poster(poster_id=3, job_id_map=2, worker_id=6, posterName=Poster3 for Job2 by Bill), workers=[Worker(worker_id=3, workerName=Jane)])]! They are:-
        Poster is Poster3 for Job2 by Bill ID is 3 mapped to JobID 2 there are 1 Workers. They are:-
    
        Worker is Jane ID is 3 (via Poster).
    There are 3 Junctions With Extra Data! They are:-
        JunctionWithExtra (Extra Data) is J2W2JKL JobID is 2 WorkerID is 2
        JunctionWithExtra (Extra Data) is J2W4MNO JobID is 2 WorkerID is 4
        JunctionWithExtra (Extra Data) is J2W6PQR JobID is 2 WorkerID is 6.
    There are 3 Workers!. They are:-
        Worker is Mary ID is 2 (via Job)
        Worker is Tom ID is 4 (via Job)
        Worker is Bill ID is 6 (via Job)
2023-03-29 11:20:35.042 D/DBINFO: Job is Job3 City is Everywhere Status is 3 JOBID is 3 OwenerID is 2.
    There are [PosterWithWorker(poster=Poster(poster_id=4, job_id_map=3, worker_id=4, posterName=Poster4 for Job3 by Tom), workers=[Worker(worker_id=4, workerName=Tom)])]! They are:-
        Poster is Poster4 for Job3 by Tom ID is 4 mapped to JobID 3 there are 1 Workers. They are:-
    
        Worker is Tom ID is 4 (via Poster).
    There are 0 Junctions With Extra Data! They are:-.
    There are 0 Workers!. They are:-
2023-03-29 11:20:35.047 D/DBINFO: Job is Job4 City is Nowhere Status is 4 JOBID is 4 OwenerID is 3.
    There are []! They are:-.
    There are 6 Junctions With Extra Data! They are:-
        JunctionWithExtra (Extra Data) is J4W1STU JobID is 4 WorkerID is 1
        JunctionWithExtra (Extra Data) is J4W2VWX JobID is 4 WorkerID is 2
        JunctionWithExtra (Extra Data) is J4W3YZ1 JobID is 4 WorkerID is 3
        JunctionWithExtra (Extra Data) is J4W4234 JobID is 4 WorkerID is 4
        JunctionWithExtra (Extra Data) is J4W5567 JobID is 4 WorkerID is 5
        JunctionWithExtra (Extra Data) is J4W6890 JobID is 4 WorkerID is 6.
    There are 6 Workers!. They are:-
        Worker is Fred ID is 1 (via Job)
        Worker is Mary ID is 2 (via Job)
        Worker is Jane ID is 3 (via Job)
        Worker is Tom ID is 4 (via Job)
        Worker is Anne ID is 5 (via Job)
        Worker is Bill ID is 6 (via Job)

可以简单地通过将JobWorkerCrossRef表作为普通表（通过@Relation）而不是Junction表来检索相应的额外数据。
因此，简而言之，为了不从junction表中获取数据，您可以通过Junction将其用作junction表。

更进一步，合并Worker和Extra数据

要获得组合的数据MapWorker和Extra，您可以使用POJO，通过@Relation Worker来获得特定的Worker详细信息。
作为后者的一个例子，你可以有：

data class JobPWE(
    @Embedded
    val job: Job,
    @Relation(
        entity = JobWorkerCrossRef::class,
        parentColumn = "job_id",
        entityColumn = "job_id"
    )
    val junctionWithExtra: List<JobWorkerCrossRefWithWorker>,
    @Relation(
        entity = Poster::class,
        parentColumn = "job_id",
        entityColumn = "job_id_map"
    )
    val posters: List<PosterWithWorker>
)

• 而不是JobPW

例如

data class JobWorkerCrossRefWithWorker(
    @Embedded
    val jwxr: JobWorkerCrossRef,
    @Relation(
        entity = Worker::class,
        parentColumn = "worker_id",
        entityColumn = "worker_id"
    )
    val workerDetail: Worker
)

沿着with（allowinggetJobsto be as is）：-

@Transaction
@Query("SELECT * FROM job")
fun getJobsV2(): List<JobPWE>

然后在活动代码中使用以下内容：

for (jpwe in dao.getJobsV2()) {
        val pli = StringBuilder()
        for (p in jpwe.posters) {
            val pwli = StringBuilder()
            for (w in p.workers) {
                pwli.append("\n\t\tWorker is ${w.workerName} ID is ${w.worker_id} (via Poster)")
            }
            pli.append("\n\tPoster is ${p.poster.posterName} ID is ${p.poster.poster_id} mapped to JobID ${p.poster.job_id_map} there are ${p.workers.size} Workers. They are:-${pwli}")
        }
        val jpel = StringBuilder()
        for (je in jpwe.junctionWithExtra) {
            jpel.append(
                "\n\tJunctionWithExtra (Extra Data) is ${je.jwxr.extraData} (from junction) " +
                        "JobID is ${je.jwxr.job_id} (from junction table) " +
                        "WorkerID is ${je.jwxr} (from junction table) " +
                        "WorkerName is ${je.workerDetail.workerName} (from Worker table related to the junction table)"
            )
        }
        Log.d(
            "DBINFOV2",
            "Job is ${jpwe.job.title} City is ${jpwe.job.city} Status is ${jpwe.job.status} JOBID is ${jpwe.job.job_id} OwnerID is ${jpwe.job.owner_id_map}" +
                    ".\nThere are ${jpwe.posters.size} posters! They are:-$pli" +
                    ".\nThere are ${jpwe.junctionWithExtra.size} Junctions With Extra Data! They are:-${jpel}"
        )
    }

然后，当使用相同的数据时，日志中的结果将显示：

2023-03-29 16:44:02.176 D/DBINFOV2: Job is Job1 City is Somewhere Status is 1 JOBID is 1 OwnerID is 1.
    There are 2 posters! They are:-
        Poster is Poster1 for Job1 by Bill ID is 1 mapped to JobID 1 there are 1 Workers. They are:-
            Worker is Fred ID is 1 (via Poster)
        Poster is Poster2 for Job1 by Anne ID is 2 mapped to JobID 1 there are 1 Workers. They are:-
            Worker is Mary ID is 2 (via Poster).
    There are 3 Junctions With Extra Data! They are:-
        JunctionWithExtra (Extra Data) is J1W1ABC (from junction) JobID is 1 (from junction table) WorkerID is JobWorkerCrossRef(job_id=1, worker_id=1, extraData=J1W1ABC) (from junction table) WorkerName is Fred (from Worker table related to the junction table)
        JunctionWithExtra (Extra Data) is J1W3DEF (from junction) JobID is 1 (from junction table) WorkerID is JobWorkerCrossRef(job_id=1, worker_id=3, extraData=J1W3DEF) (from junction table) WorkerName is Jane (from Worker table related to the junction table)
        JunctionWithExtra (Extra Data) is J1W5GHI (from junction) JobID is 1 (from junction table) WorkerID is JobWorkerCrossRef(job_id=1, worker_id=5, extraData=J1W5GHI) (from junction table) WorkerName is Anne (from Worker table related to the junction table)
2023-03-29 16:44:02.176 D/DBINFOV2: Job is Job2 City is Elsewhere Status is 2 JOBID is 2 OwnerID is 1.
    There are 1 posters! They are:-
        Poster is Poster3 for Job2 by Bill ID is 3 mapped to JobID 2 there are 1 Workers. They are:-
            Worker is Jane ID is 3 (via Poster).
    There are 3 Junctions With Extra Data! They are:-
        JunctionWithExtra (Extra Data) is J2W2JKL (from junction) JobID is 2 (from junction table) WorkerID is JobWorkerCrossRef(job_id=2, worker_id=2, extraData=J2W2JKL) (from junction table) WorkerName is Mary (from Worker table related to the junction table)
        JunctionWithExtra (Extra Data) is J2W4MNO (from junction) JobID is 2 (from junction table) WorkerID is JobWorkerCrossRef(job_id=2, worker_id=4, extraData=J2W4MNO) (from junction table) WorkerName is Tom (from Worker table related to the junction table)
        JunctionWithExtra (Extra Data) is J2W6PQR (from junction) JobID is 2 (from junction table) WorkerID is JobWorkerCrossRef(job_id=2, worker_id=6, extraData=J2W6PQR) (from junction table) WorkerName is Bill (from Worker table related to the junction table)
2023-03-29 16:44:02.176 D/DBINFOV2: Job is Job3 City is Everywhere Status is 3 JOBID is 3 OwnerID is 2.
    There are 1 posters! They are:-
        Poster is Poster4 for Job3 by Tom ID is 4 mapped to JobID 3 there are 1 Workers. They are:-
            Worker is Tom ID is 4 (via Poster).
    There are 0 Junctions With Extra Data! They are:-
2023-03-29 16:44:02.177 D/DBINFOV2: Job is Job4 City is Nowhere Status is 4 JOBID is 4 OwnerID is 3.
    There are 0 posters! They are:-.
    There are 6 Junctions With Extra Data! They are:-
        JunctionWithExtra (Extra Data) is J4W1STU (from junction) JobID is 4 (from junction table) WorkerID is JobWorkerCrossRef(job_id=4, worker_id=1, extraData=J4W1STU) (from junction table) WorkerName is Fred (from Worker table related to the junction table)
        JunctionWithExtra (Extra Data) is J4W2VWX (from junction) JobID is 4 (from junction table) WorkerID is JobWorkerCrossRef(job_id=4, worker_id=2, extraData=J4W2VWX) (from junction table) WorkerName is Mary (from Worker table related to the junction table)
        JunctionWithExtra (Extra Data) is J4W3YZ1 (from junction) JobID is 4 (from junction table) WorkerID is JobWorkerCrossRef(job_id=4, worker_id=3, extraData=J4W3YZ1) (from junction table) WorkerName is Jane (from Worker table related to the junction table)
        JunctionWithExtra (Extra Data) is J4W4234 (from junction) JobID is 4 (from junction table) WorkerID is JobWorkerCrossRef(job_id=4, worker_id=4, extraData=J4W4234) (from junction table) WorkerName is Tom (from Worker table related to the junction table)
        JunctionWithExtra (Extra Data) is J4W5567 (from junction) JobID is 4 (from junction table) WorkerID is JobWorkerCrossRef(job_id=4, worker_id=5, extraData=J4W5567) (from junction table) WorkerName is Anne (from Worker table related to the junction table)
        JunctionWithExtra (Extra Data) is J4W6890 (from junction) JobID is 4 (from junction table) WorkerID is JobWorkerCrossRef(job_id=4, worker_id=6, extraData=J4W6890) (from junction table) WorkerName is Bill (from Worker table related to the junction table)

即，组合工人和额外数据。
(One版本是一个流程，我想最好使用这个版本）
在流中 Package 与处理流一样简单。