Question

我的应用程序正在使用sqlite db，以下代码适用于手机。但是，当我在任何平板电脑上运行它时，它从表中读取时均失败，并出现以下错误。

public class DatabaseHelper extends SQLiteOpenHelper {
private static String DB_PATH = "C:/temp/";

private static String DB_NAME = "sample.db";
private SQLiteDatabase myDataBase;
private final Context myContext;
public DatabaseHelper(Context context) {
    super(context, DB_NAME, null, 1);
    this.myContext = context;
    if(android.os.Build.VERSION.SDK_INT >= 4.2){
        DB_PATH = context.getApplicationInfo().dataDir + "/databases/";
         }
    else
    {
        DB_PATH = "/data/data/" + context.getPackageName() + "/databases/";
    }
}
public void createDataBase() throws IOException {

    boolean dbExist = checkDataBase();
         if(dbExist){          
    }else{
        this.getReadableDatabase();
                  try {
            copyDataBase();

        } catch (IOException e) {               
            throw new RuntimeException(e);
        }
    }
}
private boolean checkDataBase(){
    SQLiteDatabase checkDB = null;
    try{
        String myPath = DB_PATH+DB_NAME;
        checkDB = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READONLY);
    }catch(SQLiteException e){
          }
    if(checkDB != null){
        checkDB.close();
    }
    return checkDB != null ? true : false;
}

/**
 * Copies your database from your local assets-folder to the just created empty database in the
 * system folder, from where it can be accessed and handled.
 * This is done by transfering bytestream.
 * */
private void copyDataBase() throws IOException{

    //Open your local db as the input stream
    InputStream myInput = myContext.getAssets().open(DB_NAME);
    //System.exit(0);

    // Path to the just created empty db
    String outFileName =  DB_PATH+DB_NAME;

    //Open the empty db as the output stream
    OutputStream myOutput = new FileOutputStream(outFileName);

    byte[] buffer = new byte[1024];
    int length;
    while ((length = myInput.read(buffer))>0){
        myOutput.write(buffer, 0, length);
         }
    myOutput.flush();
    myOutput.close();
    myInput.close();
}
public void openDataBase() throws SQLException {
    String myPath =  DB_PATH+DB_NAME;
    myDataBase = SQLiteDatabase.openDatabase(myPath, null, SQLiteDatabase.OPEN_READWRITE);      
}

错误消息： 2019-03-28 08：24：17.373 5791-5791 / E / SQLiteLog：（1）没有这样的表：setting_storage 2019-03-28 08：25：41.901 5791-5791 / E / SQLiteLog：（1）没有这样的表：flashcard_sets 2019-03-28 08：25：41.909 5791-5791 / E / Android运行时：致命异常：主要程序：，PID：5791 java.lang.RuntimeException：无法启动活动ComponentInfo {Main2Activity}：android.database.sqlite.SQLiteException：无此类表：flashcard_sets（代码1 SQLITE_ERROR）：，同时编译：从flashcard_sets中选择count（）在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2913）在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:3048）在android.app.servertransaction.LaunchActivityItem.execute（LaunchActivityItem.java:78）在android.app.servertransaction.TransactionExecutor.executeCallbacks（TransactionExecutor.java:108）在android.app.servertransaction.TransactionExecutor.execute（TransactionExecutor.java:68）在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1808）在android.os.Handler.dispatchMessage（Handler.java:106）在android.os.Looper.loop（Looper.java:193）在android.app.ActivityThread.main（ActivityThread.java:6669）在java.lang.reflect.Method.invoke（本机方法）在com.android.internal.os.RuntimeInit $ MethodAndArgsCaller.run（RuntimeInit.java:493）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:858）引起原因：android.database.sqlite.SQLiteException：否这样的表：flashcard_sets（代码1 SQLITE_ERROR）：，而在编译时：从flashcard_sets中选择count（）在android.database.sqlite.SQLiteConnection.nativePrepareStatement（本机方法）在android.database.sqlite.SQLiteConnection.acquirePreparedStatement（SQLiteConnection.java:903）在android.database.sqlite.SQLiteConnection.prepare（SQLiteConnection.java:514）在android.database.sqlite.SQLiteSession.prepare（SQLiteSession.java:588）在android.database.sqlite.SQLiteProgram。（SQLiteProgram.java:58）在android.database.sqlite.SQLiteQuery。（SQLiteQuery.java:37）在android.database.sqlite.SQLiteDirectCursorDriver.query（SQLiteDirectCursorDriver.java:46）在android.database.sqlite.SQLiteDatabase.rawQueryWithFactory（SQLiteDatabase.java:1408）在android.database.sqlite.SQLiteDatabase.rawQuery（SQLiteDatabase.java:1347）在model.DatabaseHelper.getNumberofRowsFlashcard_sets（DatabaseHelper.java:305）在gana.nyamas.od00259.vocbuilder.Main2Activity.addItems（Main2Activity.java:158）在gana.nyamas.od00259.vocbuilder.Main2Activity.onCreate（Main2Activity.java:107）在android.app.Activity.performCreate（Activity.java:7136）在android.app.Activity.performCreate（Activity.java:7127）在android.app.Instrumentation.callActivityOnCreate（Instrumentation.java:1271）在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2893）在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:3048）在android.app.servertransaction.LaunchActivityItem.execute（LaunchActivityItem.java:78）在android.app.servertransaction.TransactionExecutor.executeCallbacks（TransactionExecutor.java:108）在android.app.servertransaction.TransactionExecutor.execute（TransactionExecutor.java:68）在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:1808）在android.os.Handler.dispatchMessage（Handler.java:106）在android.os.Looper.loop（Looper.java:193）在android.app.ActivityThread.main（ActivityThread.java:6669）在java.lang.reflect.Method.invoke（本机方法）在com.android.internal.os.RuntimeInit $ MethodAndArgsCaller.run（RuntimeInit.java:493） com.android.internal.os.ZygoteInit.main（ZygoteInit.java:858）

平板电脑的sqlite DB读取失败

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