Room-删除查询后数据库被锁定

Question

我正在尝试从数据库中删除一行。当我第一次删除它时，该行被成功删除。尝试删除另一行后，出现错误，提示数据库未打开/已锁定。我已经发布了logcat和代码。

[此外，如果我是第一次删除一行，它将被删除；当我关闭该应用并再次将其重新打开并删除另一行时，它将起作用。仅当我在不关闭应用程序的情况下继续删除另一行时，才会出现错误。

这里是日志：

     Caused by: java.lang.IllegalStateException: The database '/data/user/0/com.basusingh.blingoo/databases/wordLayList' is not open.
        at android.database.sqlite.SQLiteDatabase.throwIfNotOpenLocked(SQLiteDatabase.java:2943)
        at android.database.sqlite.SQLiteDatabase.createSession(SQLiteDatabase.java:564)
        at android.database.sqlite.-$$Lambda$RBWjWVyGrOTsQrLCYzJ_G8Uk25Q.get(Unknown Source:2)
        at java.lang.ThreadLocal$SuppliedThreadLocal.initialValue(ThreadLocal.java:284)
        at java.lang.ThreadLocal.setInitialValue(ThreadLocal.java:180)
        at java.lang.ThreadLocal.get(ThreadLocal.java:170)
        at android.database.sqlite.SQLiteDatabase.getThreadSession(SQLiteDatabase.java:558)
        at android.database.sqlite.SQLiteProgram.getSession(SQLiteProgram.java:123)
        at android.database.sqlite.SQLiteStatement.executeUpdateDelete(SQLiteStatement.java:64)
        at androidx.sqlite.db.framework.FrameworkSQLiteStatement.executeUpdateDelete(FrameworkSQLiteStatement.java:46)
        at com.basusingh.blingoo.Database.WordLayList.WordLayListDao_Impl.DeleteWordLayList(WordLayListDao_Impl.java:94)
        at com.basusingh.blingoo.Activity.WordLayListViewer$1doTask.doInBackground(WordLayListViewer.java:156)
        at com.basusingh.blingoo.Activity.WordLayListViewer$1doTask.doInBackground(WordLayListViewer.java:148)
        at android.os.AsyncTask$2.call(AsyncTask.java:333)
        at java.util.concurrent.FutureTask.run(FutureTask.java:266)
        at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:245) 
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167) 
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641) 
        at java.lang.Thread.run(Thread.java:764) 
E/ROOM: Cannot run invalidation tracker. Is the db closed?
    android.database.sqlite.SQLiteException: no such table: room_table_modification_log (code 1 SQLITE_ERROR[1]): , while compiling: SELECT * FROM room_table_modification_log WHERE invalidated = 1;
        at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
        at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:1229)
        at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:703)
        at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
        at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:59)
        at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
        at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:46)
        at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1865)
        at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1840)
        at androidx.sqlite.db.framework.FrameworkSQLiteDatabase.query(FrameworkSQLiteDatabase.java:161)
        at androidx.room.RoomDatabase.query(RoomDatabase.java:328)
        at androidx.room.RoomDatabase.query(RoomDatabase.java:311)
        at androidx.room.InvalidationTracker$1.checkUpdatedTable(InvalidationTracker.java:415)
        at androidx.room.InvalidationTracker$1.run(InvalidationTracker.java:389)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1167)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:641)
        at java.lang.Thread.run(Thread.java:764)

这是DAO代码：

@Dao
public interface WordLayListDao {

    @Query("DELETE FROM WordLayListItems WHERE uid = :id")
    void DeleteWordLayList(int id);

}

和其他班级，

public class WordLayListDatabaseClient {

    private Context mCtx;
    private static WordLayListDatabaseClient mInstance;

    private WordLayListAppDatabase appDatabase;


    private WordLayListDatabaseClient(Context mCtx) {
        this.mCtx = mCtx;



        appDatabase = Room.databaseBuilder(mCtx, WordLayListAppDatabase.class, "wordLayList").build();
    }

    public static synchronized WordLayListDatabaseClient getInstance(Context mCtx) {
        if (mInstance == null) {
            mInstance = new WordLayListDatabaseClient(mCtx);
        }
        return mInstance;
    }

    public WordLayListAppDatabase getAppDatabase() {
        return appDatabase;
    }
}

@Database(entities = {WordLayListItems.class}, version = 1)
public abstract class WordLayListAppDatabase extends RoomDatabase {
    public abstract WordLayListDao wordLayListDao();
}

这是我调用数据库的方式：

 private void deleteLayList(){
        class doTask extends AsyncTask<Void, Void, String> {
            @Override
            protected void onPreExecute(){
                progressDialog.setTitle("Please wait");
                progressDialog.show();
            }
            @Override
            protected String doInBackground(Void... aa){
                WordLayListDatabaseClient.getInstance(WordLayListViewer.this).getAppDatabase().wordLayListDao().DeleteWordLayList(o.getID());
                return null;
            }
            @Override
            protected void onPostExecute(String var){
                progressDialog.dismiss();
                Toast.makeText(getApplicationContext(), "WordLay List Deleted", Toast.LENGTH_LONG).show();
                setResult(RESULT_OK);
                finish();
            }
        }

        doTask dt = new doTask();
        dt.execute();
    }

Answer 1

我已经通过这种方式解决了这个问题。

而不是使用单例类来插入或删除，我只是直接调用此代码：

 WordLayListAppDatabase db = Room.databaseBuilder(getApplicationContext(),
                        WordLayListAppDatabase.class, "wordLayList").build();
                db.wordLayListDao().DeleteWordLayListByObject(o);

现在，我正在使用singleton类来仅获取数据。要更新数据库，我使用上面的代码（以上始终在异步任务中调用）。