Android Room-Android Studio数据库检查器不显示数据库

我现在正在尝试学习android，我正在构建一个带有数据库的应用程序——我用过房间，但似乎无法让数据库检查器显示我的表格或确认它们存在！我有4个实体和4个DAO。我没有遇到应用程序崩溃，只是在数据库检查器中看不到我的数据库。我试图通过检查者首先检查数据库，然后再以DB为基础完成应用程序的所有LIFEDATA和逻辑。 我构建了android，并交叉检查了我的房间结构和代码实验室。我下载并运行了相同的代码实验室，我可以检查它的数据库，没有问题。我使缓存失效并重新启动

当我在主活动

onCreate（）

中使用“ViewModelProvider”将主活动链接到ViewModel时，它是否绕过了我的构造函数？它似乎不像我从构造函数中获取日志语句一样

当我为房间重构任何东西时，我进入了构建>清理然后构建>重建。   我在main activity（single activity app）>viewmodel>repository>database类中添加了日志语句，并且返回了所有日志，因此代码以正确的顺序调用

当我尝试加载数据库检查器时，我看到以下内容：；

下面是UI“向下”的代码-从主活动开始

public class MainActivity extends AppCompatActivity {

    private ViewModelTimerSetup viewModelTimerSetup;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main_activity);

        Log.d(ViewModelTimerSetup.getStaticLogTag(), "Main Activity - just before calling viewmodel");
        // generate a setupViewModel and therefore the db (vm > repository > db).
        viewModelTimerSetup = new ViewModelProvider(this, ViewModelProvider.AndroidViewModelFactory
                .getInstance(this.getApplication())).get(ViewModelTimerSetup.class);
        Log.d(ViewModelTimerSetup.getStaticLogTag(), "Main Activity - just after calling viewmodel");

视图模型

public class ViewModelTimerSetup extends AndroidViewModel {
    public static String getStaticLogTag() {
        return STATIC_LOG_TAG;
    }
    private static final String STATIC_LOG_TAG = "my_logging";

    private final LiveData<List<TimerDesign>> allTimerDesigns;
    private final LiveData<List<TimerRecords>> allTimerRecords;

    // instantiate the app repository to access the database
    private AppRepository appRepository;

    /**
     * system required constructor, also gets the DBs from the app repository
     * @param application
     */
    public ViewModelTimerSetup(@NonNull Application application) {
        super(application);

        Log.d(STATIC_LOG_TAG, "Log tag - inside ViewModelTimerSetup constructor - pre making new db");
        // instantiate the access to the repository for db access
        appRepository = new AppRepository(application);
        Log.d(STATIC_LOG_TAG, "Log tag - inside the ViewModelTimerSetup constructor - after making new db");
        allTimerDesigns = appRepository.getAllTimerDesigns();
        allTimerRecords = appRepository.getAllTimerRecords();
    }

以下是数据库类（

myDatabaseCallback

为简洁起见省略）

示例实体-所有实体都使用适当的房间注释、getter、setter和1个构造函数构建

@Entity(tableName = "timer_design")
    public class TimerDesign {
    
        @PrimaryKey(autoGenerate = true)
        @ColumnInfo(name = "timer_design_id")
        private int timerDesignID;
    
        @ColumnInfo(name = "timer_name")
        @NonNull
        private String timerName;
    
        @ColumnInfo(name = "total_duration", defaultValue = "00:00:00")
        @NonNull
        private String totalDuration;
    
        /**
         * constructor excl the id (id is autogenerated).
         * @param timerName
         */
        public TimerDesign(String timerName) {
            this.timerName = timerName;
            totalDuration = "00:00:00";
        }
    
        /**
         * setter for the ID
         * @param timerDesignID
         */
        public void setTimerDesignID(int timerDesignID) {
            this.timerDesignID = timerDesignID;
        }
    
        /**
         * getter for the id
         * @return
         */
        public int getTimerDesignID() {
            return timerDesignID;
        }
    
        /**
         * getter for the timer name
         * @return
         */
        public String getTimerName() {
            return timerName;
        }
    
        /**
         * setter for the timer name
         * @param timerName
         */
        public void setTimerName(@NonNull String timerName) {
            this.timerName = timerName;
        }
    
        /**
         * getter for the total duration
         * @return
         */
        @NonNull
        public String getTotalDuration() {
            return totalDuration;
        }
    
        /**
         * setter for the total duration
         * @param totalDuration
         */
        public void setTotalDuration(@NonNull String totalDuration) {
            this.totalDuration = totalDuration;
        }
    }

以及上述实体的DAO

@Dao
public interface TimerDesignDAO {

    // https://developer.android.com/reference/androidx/room/OnConflictStrategy.html
    @Insert(onConflict = OnConflictStrategy.IGNORE)
    void insert(TimerDesign timerDesign);

    @Update
    void update(TimerDesign timerDesign);

    @Delete
    void delete(TimerDesign timerDesign);

    // delete all timers
    @Query("DELETE FROM timer_design")
    void deleteAllTimerDesigns();

    // get a list of all designed timers
    @Query("SELECT * FROM timer_design")
    LiveData<List<TimerDesign>> getAllTimerDesigns();

    // get a single timer design
    @Query("SELECT * FROM timer_design WHERE timer_design_id = :timerID")
    LiveData<List<TimerDesign>> getOneTimerDesign(int timerID);

    // get the id of the most recently inserted timer
    @Query("SELECT MAX(timer_design_id) FROM timer_design")
    int getMostRecentInsertedTimerID();
}

---

我从设备数据目录下载了DB文件，正如注释中@MikeT所建议的那样。然后我加载到DB Browser中，发现所有4个表都按设计存在，还有几个显然是由OS和Room添加的。在初始数据库创建时请求添加的数据也存在（来自myDatabaseCallback）

---

在过去的几天里，我的Android Studio升级到了4.2.1，DB inspector正常运行。

数据库中还有什么内容吗？对此不是100%确定，但可能是在您实际添加某些内容之前，数据库不会创建I Ivan，我请求将一些对象添加到RoomDatabase内的一些表中。回调“myDatabaseCallback”，但这对数据库检查器没有影响。同时，我将转到UI，看看一旦构建了完整的UI，我是否可以像用户那样添加对象，然后我就知道这是安卓工作室的问题还是数据库的问题。你可以随时尝试通过设备浏览器查看数据库，它将位于

data/data//databases/

中。你至少希望看到

timers\u database

文件，可能还有timers\u database-wal和timers\u database-shm文件。如果这些存在，那么它与数据库检查器有关。您可以随时复制文件（全部3个）并使用SQLite工具查看它们。嗨，MikeT，好主意！我怎么没想到呢！是的，有一个

timers\u数据库

文件，一个

timers\u数据库

和一个

timers\u数据库

。这三个都有

-rw-rw---

的权限。我会复制它们并按建议检查。我想你的设备至少是安卓8？检查员必须工作。

@Entity(tableName = "timer_design")
    public class TimerDesign {
    
        @PrimaryKey(autoGenerate = true)
        @ColumnInfo(name = "timer_design_id")
        private int timerDesignID;
    
        @ColumnInfo(name = "timer_name")
        @NonNull
        private String timerName;
    
        @ColumnInfo(name = "total_duration", defaultValue = "00:00:00")
        @NonNull
        private String totalDuration;
    
        /**
         * constructor excl the id (id is autogenerated).
         * @param timerName
         */
        public TimerDesign(String timerName) {
            this.timerName = timerName;
            totalDuration = "00:00:00";
        }
    
        /**
         * setter for the ID
         * @param timerDesignID
         */
        public void setTimerDesignID(int timerDesignID) {
            this.timerDesignID = timerDesignID;
        }
    
        /**
         * getter for the id
         * @return
         */
        public int getTimerDesignID() {
            return timerDesignID;
        }
    
        /**
         * getter for the timer name
         * @return
         */
        public String getTimerName() {
            return timerName;
        }
    
        /**
         * setter for the timer name
         * @param timerName
         */
        public void setTimerName(@NonNull String timerName) {
            this.timerName = timerName;
        }
    
        /**
         * getter for the total duration
         * @return
         */
        @NonNull
        public String getTotalDuration() {
            return totalDuration;
        }
    
        /**
         * setter for the total duration
         * @param totalDuration
         */
        public void setTotalDuration(@NonNull String totalDuration) {
            this.totalDuration = totalDuration;
        }
    }

@Dao
public interface TimerDesignDAO {

    // https://developer.android.com/reference/androidx/room/OnConflictStrategy.html
    @Insert(onConflict = OnConflictStrategy.IGNORE)
    void insert(TimerDesign timerDesign);

    @Update
    void update(TimerDesign timerDesign);

    @Delete
    void delete(TimerDesign timerDesign);

    // delete all timers
    @Query("DELETE FROM timer_design")
    void deleteAllTimerDesigns();

    // get a list of all designed timers
    @Query("SELECT * FROM timer_design")
    LiveData<List<TimerDesign>> getAllTimerDesigns();

    // get a single timer design
    @Query("SELECT * FROM timer_design WHERE timer_design_id = :timerID")
    LiveData<List<TimerDesign>> getOneTimerDesign(int timerID);

    // get the id of the most recently inserted timer
    @Query("SELECT MAX(timer_design_id) FROM timer_design")
    int getMostRecentInsertedTimerID();
}

2021-05-12 15:02:37.798 xxx D/my_logging: Main Activity - just before calling viewmodel
2021-05-12 15:02:37.799 xxx D/my_logging: Log tag - inside ViewModelTimerSetup constructor - pre making new db
2021-05-12 15:02:37.803 xxx D/my_logging: Repository - just before calling new database instance
2021-05-12 15:02:37.811 xxx D/my_logging: Database - before building new database instance
2021-05-12 15:02:37.841 xxx D/my_logging: xxx.AllTimersDatabase_Impl@cf67ddc
2021-05-12 15:02:37.841 xxx D/my_logging: Repository - just after calling new database instance
2021-05-12 15:02:37.862 xxx D/my_logging: Log tag - inside the ViewModelTimerSetup constructor - after making new db
2021-05-12 15:02:37.865 xxx D/my_logging: Main Activity - just after calling viewmodel
2021-05-12 15:02:38.349 xxx D/my_logging: Log tag - inside ViewModelTimerSetup constructor - pre making new db
2021-05-12 15:02:38.349 xxx D/my_logging: Repository - just before calling new database instance
2021-05-12 15:02:38.349 xxx D/my_logging: xxx.AllTimersDatabase_Impl@cf67ddc
2021-05-12 15:02:38.350 xxx D/my_logging: Repository - just after calling new database instance
2021-05-12 15:02:38.350 xxx D/my_logging: Log tag - inside the ViewModelTimerSetup constructor - after making new db