Question

我已经尝试了很多时间，但是无法得到如何解决这个问题，SQL Broswser上的一切正常，SQL查询运行没有得到但是在运行问题时，而不是获取

Caused by: android.database.sqlite.SQLiteException: no such table

。请告诉我，这是怎么回事。

 public class DatabaseHelper extends SQLiteOpenHelper {
private Context mycontext;

private String DB_PATH = "/data/data/com.tosts.yummi/databases/";
private static String DB_NAME = "hotss";
private static String DB_TABLE = "kathas";

public SQLiteDatabase myDataBase;

private int id;
private static final int DATABASE_VERSION = 3;
private String TAG = "horror";

public DatabaseHelper(Context context) throws IOException {
    super(context, DB_NAME, null, DATABASE_VERSION);
    this.mycontext = context;
    boolean dbexist = checkdatabase();
    if (dbexist) {
        // System.out.println("Database exists");
        opendatabase();
    } else {
        // System.out.println("Database doesn't exist");
        createdatabase();
    }
}

public void createdatabase() throws IOException {
    boolean dbexist = checkdatabase();
    if (dbexist) {
        System.out.println(" Database exists.");
    } else {
        this.getReadableDatabase();
        try {
            copydatabase();
            //myDataBase.close();
        } catch (IOException e) {
            throw new Error("Error copying database");
        }
    }
}

private boolean checkdatabase() {
    // SQLiteDatabase checkdb = null;
    boolean checkdb = false;
    try {
        String myPath = DB_PATH + DB_NAME;
        File dbfile = new File(myPath);
        checkdb = SQLiteDatabase.openDatabase(myPath, null,
                SQLiteDatabase.OPEN_READWRITE) != null;
        checkdb = dbfile.exists();

    } catch (SQLiteException e) {
        System.out.println("Database doesn't exist");
    }

    return checkdb;
}

private void copydatabase() throws IOException {
    // Open your local db as the input stream
    InputStream myinput = mycontext.getAssets().open(DB_NAME);
    String outfilename = DB_PATH + DB_NAME;
    OutputStream myoutput = new FileOutputStream(outfilename);
    Log.d(TAG, "COpt Test->"+"InputStream->"+myinput+"--?"+outfilename+"---"+myoutput);
    byte[] buffer = new byte[1024];// transfer byte to inputfile to
                                    // outputfile
    int length;
    while ((length = myinput.read(buffer)) > 0) {
        myoutput.write(buffer, 0, length);
    }
    myoutput.flush();// Close the streams
    myoutput.close();
    myinput.close();
}

public void opendatabase() throws SQLException {
    // Open the database
    String mypath = DB_PATH + DB_NAME;
    myDataBase = SQLiteDatabase.openDatabase(mypath, null,
            SQLiteDatabase.OPEN_READONLY);

}

public synchronized void close() {
    if (myDataBase != null) {
        myDataBase.close();
    }
    super.close();
}

@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    //db.execSQL("DROP TABLE IF EXISTS " + DB_TABLE);
    //onCreate(db);
}

// This will return a cursor containing database records
public Cursor data() {

    Cursor c;
    c = myDataBase.query(DB_TABLE, null, null, null, null, null, null);
    return c;
}

@Override
public void onCreate(SQLiteDatabase arg0) {
    // TODO Auto-generated method stub

}

   public List<String> getAllKatha(int category){
        List<String> labels = new ArrayList<String>();
        //List<String> ids = new ArrayList<String>();
        // Select All Query
        String selectQuery = "SELECT * FROM kathas where category =" + category;
        Log.d(TAG, "--->>>"+selectQuery);
        myDataBase = this.getReadableDatabase();
        Cursor cursor = myDataBase.rawQuery(selectQuery, null);

        // looping through all rows and adding to list
        if (cursor.moveToFirst()) {
            do {
                labels.add(cursor.getString(1));
                //ids.add(cursor.getString(0));
            } while (cursor.moveToNext());
        }

        // closing connection
        cursor.close();
        myDataBase.close();

        // returning lables
        return labels;
    }

我在log cat上得到这样的结果：

12-23 19:37:51.503: E/AndroidRuntime(1527): Caused by: android.database.sqlite.SQLiteException: no such table: kathas (code 1): , while compiling: SELECT * FROM kathas where category =3
12-23 19:37:51.503: E/AndroidRuntime(1527):     at android.database.sqlite.SQLiteConnection.nativePrepareStatement(Native Method)
12-23 19:37:51.503: E/AndroidRuntime(1527):     at android.database.sqlite.SQLiteConnection.acquirePreparedStatement(SQLiteConnection.java:882)
12-23 19:37:51.503: E/AndroidRuntime(1527):     at android.database.sqlite.SQLiteConnection.prepare(SQLiteConnection.java:493)
12-23 19:37:51.503: E/AndroidRuntime(1527):     at android.database.sqlite.SQLiteSession.prepare(SQLiteSession.java:588)
12-23 19:37:51.503: E/AndroidRuntime(1527):     at android.database.sqlite.SQLiteProgram.<init>(SQLiteProgram.java:58)
12-23 19:37:51.503: E/AndroidRuntime(1527):     at android.database.sqlite.SQLiteQuery.<init>(SQLiteQuery.java:37)
12-23 19:37:51.503: E/AndroidRuntime(1527):     at android.database.sqlite.SQLiteDirectCursorDriver.query(SQLiteDirectCursorDriver.java:44)
12-23 19:37:51.503: E/AndroidRuntime(1527):     at android.database.sqlite.SQLiteDatabase.rawQueryWithFactory(SQLiteDatabase.java:1314)
12-23 19:37:51.503: E/AndroidRuntime(1527):     at android.database.sqlite.SQLiteDatabase.rawQuery(SQLiteDatabase.java:1253)
12-23 19:37:51.503: E/AndroidRuntime(1527):     at com.nepal.nepalisexstories.database.DatabaseHelper.getAllKatha(DatabaseHelper.java:139)
12-23 19:37:51.503: E/AndroidRuntime(1527):     at com.nepal.nepalisexstories.DisplayTitle.onCreate(DisplayTitle.java:70)

实际上是在MainActivity.java上执行此操作

titles = db.getAllKatha(category); ///(DisplayTitle.java:70)

先谢谢。

Answer 1

错误是显式安静的，表“kathas”尚未创建，这是因为您在SQLiteOpenHelper的“onCreate”方法中没有任何内容，并且在您用于创建数据库的方法中出现了问题，这是一个关于数据库创建的糟糕实现，你应该使用在SQLiteOpenHelper的onCreate方法中传递的SQLiteDatabase参数，我也注意到你正在使用onUpgrade方法调用没有任何东西的“onCreate”，所以如果您更新数据库，实际上没有发生任何事情。

Answer 2

您的onCreate方法中没有任何内容，但这并不是那么糟糕，因为您正在复制现有数据库。真正糟糕的是，你正在执行的onUpgrade方法：

DROP TABLE IF EXISTS kathas

然后你打电话给你的onCreate什么都不做。

显然，找不到你的表 - 因为你明确地删除了它。

引起：android.database.sqlite.SQLiteException：在Android中的sqlite中没有这样的表

2 个答案: