Question

我更改了数据库用户版本
在我创建的课程中，我更改了超级（...）
在onupgrade方法中，我删除了数据库并通过应用程序中的副本创建了一个新数据库。
我已经在stackoverflow上检查了这个问题的所有答案。每次编译似乎都失败了。

我试过网络寻找一个似乎逃避我的解决方案。

我将不胜感激。

课程如下：

public class DBAdapter extends SQLiteOpenHelper {
    // DBPATH uses the default system path for a given application
    // /data/data/<app namespace> , which in our example will be
    // com.wordpress.arogyavidya.mooligaimarmam
    private static String DBPATH = "/data/data/com.wordpress.arogyavidya.mooligaimarmam/databases/";
    private static String DBNAME = "mooligaimarmam.db";
    //  private static String DATABASE_TABLE = "lkgchef";
//  static final String KEY_ROWID = "_id";
//  static final String KEY_NAME = "name";
//  static final String KEY_DETAIL = "desc";
    private SQLiteDatabase myDatabase;
    private final Context myContext;

    // constructor
    public DBAdapter(Context context) {
        super(context, DBNAME, null, 3);
        this.myContext = context;
        //DBPATH = this.myContext.getDatabasePath("mooligaimarmam.db").getPath();
    }

    // create an empty db, and replace with our chosen db
    public void createDatabase() throws IOException {
        if (!checkDatabase()) {
            this.getWritableDatabase();
            try {
                copyDatabase();
            } catch (IOException e) {
                throw new Error("Error copying database from system assets");
            }
        }
    }

    // Check if our database already exists
    private boolean checkDatabase() {
        SQLiteDatabase checkableDatabase = null;
        try {
            checkableDatabase = SQLiteDatabase.openDatabase(DBPATH+DBNAME,
                    null, SQLiteDatabase.OPEN_READONLY);
        } catch (SQLiteException e) {

            // our database doesn't exist, so we'll return false below.
        }
        if (checkableDatabase != null) {
            checkableDatabase.close();
        }
        return checkableDatabase != null ? true : false;
    }

    // Copy our database from the Application's assets over the empty DB for use
    private void copyDatabase() throws IOException {
        InputStream myInput = myContext.getAssets().open(DBNAME);
        OutputStream myOutput = new FileOutputStream(DBPATH+DBNAME);
        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 {
        myDatabase = SQLiteDatabase.openDatabase(DBPATH + DBNAME, null,
                SQLiteDatabase.OPEN_READWRITE);
        /*myDatabase = SQLiteDatabase.openDatabase(DBPATH, null,
                SQLiteDatabase.OPEN_READWRITE);*/
    }

    @Override
    public synchronized void close() {
        if (myDatabase != null)
            myDatabase.close();
        super.close();
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        // Handle creation tasks, etc.
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // Handle upgrade tasks, etc.
        myDatabase.close();
        myContext.deleteDatabase(DBPATH+DBNAME);

        try {
            this.createDatabase();
        } catch (IOException e) {
            throw new Error("Error copying database from system assets");
        }
    }
}

感谢。

Answer 1

尝试一次！不要删除数据库，只需删除表。这对我来说每次都适用。

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

android.database.sqlite.SQLiteException：没有这样的表：cures（代码1）：

1 个答案: