当前位置: 首页 > 知识库问答 >
问题:

Android Sqlite onupgrade从数据库删除表

江文斌
2023-03-14

附注。我对Sqlite没有太多的经验

共有1个答案

丁成弘
2023-03-14

下面是用于回答前一个问题(链接在下面)的代码,修改后包含了一个新方法,即databaseasethandler.java中的restoreTable。

该方法将从备份的数据库中复制传递的任何表(在从asset文件夹复制新数据库时进行复制(根据前面的答案))。它不包括检查是否存在传递的表的复杂情况。

它将打开两个SQLiteDatabase实例:新数据库和旧备份数据库。从旧数据库中提取所有行,并将它们插入到新数据库中同名的表中。

这种方法,就其本身而言是:-

/**
 *
 * @param context   The context so that the respective package is used
 * @param dbname    The name of the database (the old will have -backup appended)
 * @param table     The table from which to copy the data
 */
public static void restoreTable(Context context, String dbname, String table) {
    ContentValues cv = new ContentValues();
    SQLiteDatabase dbnew = SQLiteDatabase.openDatabase(context.getDatabasePath(dbname).toString(), null,SQLiteDatabase.OPEN_READWRITE);
    SQLiteDatabase dbold = SQLiteDatabase.openDatabase(context.getDatabasePath(dbname + backup).toString(),null,SQLiteDatabase.OPEN_READONLY);
    Cursor csr = dbold.query(table,null,null,null,null,null,null);
    dbnew.beginTransaction();
    while (csr.moveToNext()) {
        cv.clear();
        int offset = 0;
        for (String column: csr.getColumnNames()) {
            switch (csr.getType(offset++)){
                case Cursor.FIELD_TYPE_NULL:
                    break;
                case Cursor.FIELD_TYPE_INTEGER:
                    cv.put(column,csr.getLong(csr.getColumnIndex(column)));
                    break;
                case Cursor.FIELD_TYPE_FLOAT:
                    cv.put(column,csr.getFloat(csr.getColumnIndex(column)));
                    break;
                case Cursor.FIELD_TYPE_STRING:
                    cv.put(column,csr.getString(csr.getColumnIndex(column)));
                    break;
                case Cursor.FIELD_TYPE_BLOB:
                    cv.put(column,csr.getBlob(csr.getColumnIndex(column)));
            }
        }
        dbnew.insert(DatabaseHelper.TABLE_BOOKMARK,null,cv);
    }
    dbnew.setTransactionSuccessful();
    dbnew.endTransaction();
    csr.close();
    dbnew.close();
    dbold.close();
}
  • 需要将此方法添加到上一个答案中的DatabaseAssetHandler代码中。

为了方便对上面的测试,对databasehelper.java做了一些更改,现在是:-

public class DatabaseHelper extends SQLiteOpenHelper {

    private  static final String DB_NAME = "dictionary.db";
    private static final int DB_VERSION = 2;
    public static final String TABLE_DICTIONARY = "dictionary";
    public static final String TABLE_BOOKMARK= "bookmark";
    public static final String COL_ID = "id";
    public static final String COL_WORD = "word";
    public static final String COL_DEFINITION = "definition";
    public static final String COL_WORID = "wordid"; //<<<<<<<<<< ADDED
    public Context mcontext;
    public SQLiteDatabase mDatabase;

    public DatabaseHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
        this.mcontext = context;
        Log.d("DBVERSION","The Database Version (as hard coded) is " + String.valueOf(DB_VERSION));

        int dbversion = DatabaseAssetHandler.getVersionFromDBFile(context,DB_NAME);
        Log.d("DBVERSION","The Database Version (as per the database file) is " + String.valueOf(dbversion));

        // Copy the Database if no database exists
        if (!DatabaseAssetHandler.checkDataBase(context,DB_NAME)) {
            DatabaseAssetHandler.copyDataBase(context,DB_NAME,true,DB_VERSION);
        } else {
            if (DB_VERSION > dbversion && DatabaseAssetHandler.checkDataBase(context, DB_NAME)) {
                DatabaseAssetHandler.copyDataBase(context, DB_NAME, true, DB_VERSION);
                DatabaseAssetHandler.restoreTable(context,DB_NAME,TABLE_BOOKMARK); //<<<<<<<<<< ADDED for keeping the BOOKMARKS
                DatabaseAssetHandler.clearForceBackups(context, DB_NAME); // Clear the backups
            }
        }
        mDatabase = this.getWritableDatabase();
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    }

    public void openDatabase() throws SQLException {
        mDatabase = this.getWritableDatabase();
    }

    //<<<<<<<<<< ADDED to allow some bookmarks to be added
    public long addBookMark(long wordid) {
        ContentValues cv = new ContentValues();
        cv.put(DatabaseHelper.COL_WORID,wordid);
        return mDatabase.insert(DatabaseHelper.TABLE_BOOKMARK,null,cv);
    }

    // Added to retrieve the database name (could make DB_NAME public)
    public String getDBNAME() {
        return this.DB_NAME;
    }

    //ADDED to dump the bookmarks along with the related word and definition
    public void logBookmarksWithWord() {

        String table_part = TABLE_BOOKMARK +
                " JOIN " + TABLE_DICTIONARY +
                " ON " + COL_WORID +
                " = " + TABLE_DICTIONARY + "." + COL_ID;
        String[] columns = new String[]{TABLE_BOOKMARK + "." + COL_ID, COL_WORID, COL_WORD, COL_DEFINITION};
        Cursor csr = mDatabase.query(table_part,columns,null,null,null,null,COL_WORD);
        DatabaseUtils.dumpCursor(csr);
        csr.close();
    }

    @Override
    public synchronized void close() {
        if (mDatabase != null)
            mDatabase.close();
        super.close();
    }
}
public class MainActivity extends AppCompatActivity {

    DatabaseHelper mDBHlpr;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mDBHlpr = new DatabaseHelper(this);
        Cursor csr = mDBHlpr.getWritableDatabase().query(
                DatabaseHelper.TABLE_DICTIONARY,
                null,null,null,null,null,null
        );
        DatabaseUtils.dumpCursor(csr);
        //<<<<<<<<<< ADDED CODE
        // Add a couple of bookmarks only if database is copied for testing
        if (DatabaseUtils.queryNumEntries(mDBHlpr.mDatabase,DatabaseHelper.TABLE_BOOKMARK) < 1) {
            mDBHlpr.addBookMark(1);
            mDBHlpr.addBookMark(3);
        }
        // Always dump the bookmarks to the log
        mDBHlpr.logBookmarksWithWord();
        //<<<<<<<<<< END OF ADDED CODE
        csr.close();
    }
}
    null
04-22 18:06:17.603 8734-8734/? D/DBVERSION: The Database Version (as hard coded) is 1
04-22 18:06:17.603 8734-8734/? D/DBVERSION: The Database Version (as per the database file) is -666666666
04-22 18:06:17.603 8734-8734/? D/DBPATH: DB Path is /data/user/0/m.example.so55711282dictionary/databases/dictionary.db
04-22 18:06:17.603 8734-8734/? D/COPYDATABASE: Initiated Copy of the database file dictionary.db from the assets folder.
04-22 18:06:17.603 8734-8734/? D/COPYDATABASE: Asset file dictionary.db found so attmepting to copy to /data/user/0/m.example.so55711282dictionary/databases/dictionary.db
04-22 18:06:17.604 8734-8734/? D/COPYDATABASE: Attempting copy of block 1 which has 4096 bytes.
04-22 18:06:17.604 8734-8734/? D/COPYDATABASE: Attempting copy of block 2 which has 4096 bytes.
04-22 18:06:17.604 8734-8734/? D/COPYDATABASE: Attempting copy of block 3 which has 4096 bytes.
04-22 18:06:17.604 8734-8734/? D/COPYDATABASE: Finished copying Database dictionary.db from the assets folder, to  /data/user/0/m.example.so55711282dictionary/databases/dictionary.db12288were copied, in 3 blocks of size 4096.
04-22 18:06:17.604 8734-8734/? D/COPYDATABASE: All Streams have been flushed and closed.
04-22 18:06:17.625 8734-8734/? I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@3396ef
04-22 18:06:17.625 8734-8734/? I/System.out: 0 {
04-22 18:06:17.625 8734-8734/? I/System.out:    id=1
04-22 18:06:17.625 8734-8734/? I/System.out:    word=Apple
04-22 18:06:17.625 8734-8734/? I/System.out:    definition=Thing that drops from an Apple Tree.
04-22 18:06:17.625 8734-8734/? I/System.out: }
04-22 18:06:17.625 8734-8734/? I/System.out: 1 {
04-22 18:06:17.625 8734-8734/? I/System.out:    id=2
04-22 18:06:17.625 8734-8734/? I/System.out:    word=Bucket
04-22 18:06:17.625 8734-8734/? I/System.out:    definition=Hand held container with carrying hanlde.
04-22 18:06:17.625 8734-8734/? I/System.out: }
04-22 18:06:17.625 8734-8734/? I/System.out: <<<<<


04-22 18:06:17.631 8734-8734/? D/BOOKMARKDUMP: Dumping the bookmarks table to the log.
04-22 18:06:17.631 8734-8734/? I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@9ce45fc
04-22 18:06:17.631 8734-8734/? I/System.out: 0 {
04-22 18:06:17.631 8734-8734/? I/System.out:    id=1
04-22 18:06:17.631 8734-8734/? I/System.out:    wordid=1
04-22 18:06:17.631 8734-8734/? I/System.out:    word=Apple
04-22 18:06:17.631 8734-8734/? I/System.out:    definition=Thing that drops from an Apple Tree.
04-22 18:06:17.631 8734-8734/? I/System.out: }
04-22 18:06:17.631 8734-8734/? I/System.out: <<<<<

只需再运行一次,没有任何更改,因此没有副本书签存在。

04-22 18:40:56.304 8858-8858/m.example.so55711282dictionary D/DBVERSION: The Database Version (as hard coded) is 1
04-22 18:40:56.304 8858-8858/m.example.so55711282dictionary D/DBVERSION: The Database Version (as per the database file) is 1
04-22 18:40:56.304 8858-8858/m.example.so55711282dictionary D/DBPATH: DB Path is /data/user/0/m.example.so55711282dictionary/databases/dictionary.db
04-22 18:40:56.308 8858-8858/m.example.so55711282dictionary I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@11697ce
04-22 18:40:56.308 8858-8858/m.example.so55711282dictionary I/System.out: 0 {
04-22 18:40:56.308 8858-8858/m.example.so55711282dictionary I/System.out:    id=1
04-22 18:40:56.308 8858-8858/m.example.so55711282dictionary I/System.out:    word=Apple
04-22 18:40:56.308 8858-8858/m.example.so55711282dictionary I/System.out:    definition=Thing that drops from an Apple Tree.
04-22 18:40:56.308 8858-8858/m.example.so55711282dictionary I/System.out: }
04-22 18:40:56.308 8858-8858/m.example.so55711282dictionary I/System.out: 1 {
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary I/System.out:    id=2
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary I/System.out:    word=Bucket
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary I/System.out:    definition=Hand held container with carrying hanlde.
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary I/System.out: }
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary I/System.out: <<<<<
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary D/BOOKMARKDUMP: Dumping the bookmarks table to the log.
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@3396ef
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary I/System.out: 0 {
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary I/System.out:    id=1
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary I/System.out:    wordid=1
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary I/System.out:    word=Apple
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary I/System.out:    definition=Thing that drops from an Apple Tree.
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary I/System.out: }
04-22 18:40:56.309 8858-8858/m.example.so55711282dictionary I/System.out: <<<<<

引入了新版本的数据库,DB_VERSION更改为2(更多的单词,所以id为3的word的书签中有一个相关的单词)。复制了数据库的新版本。这两个书签被保留了下来。

04-22 18:44:58.749 8975-8975/? D/DBVERSION: The Database Version (as hard coded) is 2
04-22 18:44:58.749 8975-8975/? D/DBVERSION: The Database Version (as per the database file) is 1
04-22 18:44:58.749 8975-8975/? D/DBPATH: DB Path is /data/user/0/m.example.so55711282dictionary/databases/dictionary.db
04-22 18:44:58.749 8975-8975/? D/DBPATH: DB Path is /data/user/0/m.example.so55711282dictionary/databases/dictionary.db
04-22 18:44:58.750 8975-8975/? D/COPYDATABASE: Initiated Copy of the database file dictionary.db from the assets folder.
04-22 18:44:58.750 8975-8975/? D/COPYDATABASE: Asset file dictionary.db found so attmepting to copy to /data/user/0/m.example.so55711282dictionary/databases/dictionary.db
04-22 18:44:58.750 8975-8975/? D/COPYDATABASE: Attempting copy of block 1 which has 4096 bytes.
04-22 18:44:58.750 8975-8975/? D/COPYDATABASE: Attempting copy of block 2 which has 4096 bytes.
04-22 18:44:58.750 8975-8975/? D/COPYDATABASE: Attempting copy of block 3 which has 4096 bytes.
04-22 18:44:58.750 8975-8975/? D/COPYDATABASE: Finished copying Database dictionary.db from the assets folder, to  /data/user/0/m.example.so55711282dictionary/databases/dictionary.db12288were copied, in 3 blocks of size 4096.
04-22 18:44:58.750 8975-8975/? D/COPYDATABASE: All Streams have been flushed and closed.
04-22 18:44:58.783 8975-8975/? I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@10862da
04-22 18:44:58.784 8975-8975/? I/System.out: 0 {
04-22 18:44:58.784 8975-8975/? I/System.out:    id=1
04-22 18:44:58.784 8975-8975/? I/System.out:    word=Apple
04-22 18:44:58.784 8975-8975/? I/System.out:    definition=Thing that drops from an Apple Tree.
04-22 18:44:58.784 8975-8975/? I/System.out: }
04-22 18:44:58.784 8975-8975/? I/System.out: 1 {
04-22 18:44:58.784 8975-8975/? I/System.out:    id=2
04-22 18:44:58.784 8975-8975/? I/System.out:    word=Bucket
04-22 18:44:58.784 8975-8975/? I/System.out:    definition=Hand held container with carrying hanlde.
04-22 18:44:58.784 8975-8975/? I/System.out: }
04-22 18:44:58.784 8975-8975/? I/System.out: 2 {
04-22 18:44:58.784 8975-8975/? I/System.out:    id=3
04-22 18:44:58.784 8975-8975/? I/System.out:    word=Yelllow
04-22 18:44:58.784 8975-8975/? I/System.out:    definition=A colour.
04-22 18:44:58.784 8975-8975/? I/System.out: }
04-22 18:44:58.784 8975-8975/? I/System.out: 3 {
04-22 18:44:58.784 8975-8975/? I/System.out:    id=4
04-22 18:44:58.784 8975-8975/? I/System.out:    word=Zebra
04-22 18:44:58.784 8975-8975/? I/System.out:    definition=A balck and white, horse-like animal.
04-22 18:44:58.784 8975-8975/? I/System.out: }
04-22 18:44:58.784 8975-8975/? I/System.out: <<<<<
04-22 18:44:58.784 8975-8975/? D/BOOKMARKDUMP: Dumping the bookmarks table to the log.
04-22 18:44:58.785 8975-8975/? I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@d4cb30b
04-22 18:44:58.785 8975-8975/? I/System.out: 0 {
04-22 18:44:58.785 8975-8975/? I/System.out:    id=1
04-22 18:44:58.785 8975-8975/? I/System.out:    wordid=1
04-22 18:44:58.785 8975-8975/? I/System.out:    word=Apple
04-22 18:44:58.785 8975-8975/? I/System.out:    definition=Thing that drops from an Apple Tree.
04-22 18:44:58.785 8975-8975/? I/System.out: }
04-22 18:44:58.785 8975-8975/? I/System.out: 1 {
04-22 18:44:58.785 8975-8975/? I/System.out:    id=2
04-22 18:44:58.785 8975-8975/? I/System.out:    wordid=3
04-22 18:44:58.785 8975-8975/? I/System.out:    word=Yelllow
04-22 18:44:58.785 8975-8975/? I/System.out:    definition=A colour.
04-22 18:44:58.785 8975-8975/? I/System.out: }
04-22 18:44:58.785 8975-8975/? I/System.out: <<<<<

没有任何改变,因此没有数据库副本书签仍然保留。

04-22 18:47:19.300 9047-9047/m.example.so55711282dictionary D/DBVERSION: The Database Version (as hard coded) is 2
04-22 18:47:19.300 9047-9047/m.example.so55711282dictionary D/DBVERSION: The Database Version (as per the database file) is 2
04-22 18:47:19.300 9047-9047/m.example.so55711282dictionary D/DBPATH: DB Path is /data/user/0/m.example.so55711282dictionary/databases/dictionary.db
04-22 18:47:19.302 9047-9047/m.example.so55711282dictionary I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@11697ce
04-22 18:47:19.302 9047-9047/m.example.so55711282dictionary I/System.out: 0 {
04-22 18:47:19.302 9047-9047/m.example.so55711282dictionary I/System.out:    id=1
04-22 18:47:19.302 9047-9047/m.example.so55711282dictionary I/System.out:    word=Apple
04-22 18:47:19.302 9047-9047/m.example.so55711282dictionary I/System.out:    definition=Thing that drops from an Apple Tree.
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: }
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: 1 {
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    id=2
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    word=Bucket
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    definition=Hand held container with carrying hanlde.
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: }
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: 2 {
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    id=3
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    word=Yelllow
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    definition=A colour.
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: }
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: 3 {
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    id=4
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    word=Zebra
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    definition=A balck and white, horse-like animal.
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: }
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: <<<<<
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary D/BOOKMARKDUMP: Dumping the bookmarks table to the log.
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@3396ef
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: 0 {
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    id=1
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    wordid=1
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    word=Apple
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    definition=Thing that drops from an Apple Tree.
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: }
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: 1 {
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    id=2
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    wordid=3
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    word=Yelllow
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out:    definition=A colour.
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: }
04-22 18:47:19.303 9047-9047/m.example.so55711282dictionary I/System.out: <<<<<
04-22 18:50:55.297 9243-9243/m.example.so55711282dictionary D/DBVERSION: The Database Version (as hard coded) is 2
04-22 18:50:55.297 9243-9243/m.example.so55711282dictionary D/DBVERSION: The Database Version (as per the database file) is -666666666
04-22 18:50:55.297 9243-9243/m.example.so55711282dictionary D/DBPATH: DB Path is /data/user/0/m.example.so55711282dictionary/databases/dictionary.db
04-22 18:50:55.297 9243-9243/m.example.so55711282dictionary D/COPYDATABASE: Initiated Copy of the database file dictionary.db from the assets folder.
04-22 18:50:55.297 9243-9243/m.example.so55711282dictionary D/COPYDATABASE: Asset file dictionary.db found so attmepting to copy to /data/user/0/m.example.so55711282dictionary/databases/dictionary.db
04-22 18:50:55.297 9243-9243/m.example.so55711282dictionary D/COPYDATABASE: Attempting copy of block 1 which has 4096 bytes.
04-22 18:50:55.298 9243-9243/m.example.so55711282dictionary D/COPYDATABASE: Attempting copy of block 2 which has 4096 bytes.
04-22 18:50:55.298 9243-9243/m.example.so55711282dictionary D/COPYDATABASE: Attempting copy of block 3 which has 4096 bytes.
04-22 18:50:55.298 9243-9243/m.example.so55711282dictionary D/COPYDATABASE: Finished copying Database dictionary.db from the assets folder, to  /data/user/0/m.example.so55711282dictionary/databases/dictionary.db12288were copied, in 3 blocks of size 4096.
04-22 18:50:55.298 9243-9243/m.example.so55711282dictionary D/COPYDATABASE: All Streams have been flushed and closed.
04-22 18:50:55.320 9243-9243/m.example.so55711282dictionary I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@3396ef
04-22 18:50:55.320 9243-9243/m.example.so55711282dictionary I/System.out: 0 {
04-22 18:50:55.320 9243-9243/m.example.so55711282dictionary I/System.out:    id=1
04-22 18:50:55.320 9243-9243/m.example.so55711282dictionary I/System.out:    word=Apple
04-22 18:50:55.320 9243-9243/m.example.so55711282dictionary I/System.out:    definition=Thing that drops from an Apple Tree.
04-22 18:50:55.320 9243-9243/m.example.so55711282dictionary I/System.out: }
04-22 18:50:55.320 9243-9243/m.example.so55711282dictionary I/System.out: 1 {
04-22 18:50:55.320 9243-9243/m.example.so55711282dictionary I/System.out:    id=2
04-22 18:50:55.320 9243-9243/m.example.so55711282dictionary I/System.out:    word=Bucket
04-22 18:50:55.321 9243-9243/m.example.so55711282dictionary I/System.out:    definition=Hand held container with carrying hanlde.
04-22 18:50:55.321 9243-9243/m.example.so55711282dictionary I/System.out: }
04-22 18:50:55.321 9243-9243/m.example.so55711282dictionary I/System.out: 2 {
04-22 18:50:55.321 9243-9243/m.example.so55711282dictionary I/System.out:    id=3
04-22 18:50:55.321 9243-9243/m.example.so55711282dictionary I/System.out:    word=Yelllow
04-22 18:50:55.321 9243-9243/m.example.so55711282dictionary I/System.out:    definition=A colour.
04-22 18:50:55.321 9243-9243/m.example.so55711282dictionary I/System.out: }
04-22 18:50:55.321 9243-9243/m.example.so55711282dictionary I/System.out: 3 {
04-22 18:50:55.321 9243-9243/m.example.so55711282dictionary I/System.out:    id=4
04-22 18:50:55.321 9243-9243/m.example.so55711282dictionary I/System.out:    word=Zebra
04-22 18:50:55.321 9243-9243/m.example.so55711282dictionary I/System.out:    definition=A balck and white, horse-like animal.
04-22 18:50:55.321 9243-9243/m.example.so55711282dictionary I/System.out: }
04-22 18:50:55.321 9243-9243/m.example.so55711282dictionary I/System.out: <<<<<
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary D/BOOKMARKDUMP: Dumping the bookmarks table to the log.
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out: >>>>> Dumping cursor android.database.sqlite.SQLiteCursor@9ce45fc
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out: 0 {
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out:    id=1
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out:    wordid=1
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out:    word=Apple
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out:    definition=Thing that drops from an Apple Tree.
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out: }
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out: 1 {
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out:    id=2
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out:    wordid=3
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out:    word=Yelllow
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out:    definition=A colour.
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out: }
04-22 18:50:55.328 9243-9243/m.example.so55711282dictionary I/System.out: <<<<<
 类似资料:
  • 我是JSP的新手,我正在尝试创建一个web界面,用户可以在该界面中输入他们想要删除的信息,并且该信息将在数据库表中删除。 在这里,他们应该输入和,然后应该删除具有两个指定ID的任何数据。但是,它不是从表中删除的。我有个例外 数组索引越界 下面是我的代码:

  • 我制作了一个JTable,其中填充了数据库中的数据。它从textfields中获取数据并将其添加到表和数据库中。问题是我有一个删除按钮,我让它从表本身删除选定的行(使用defaultTableModel),但它不会从实际的数据库中删除该数据。当我再次运行该程序时,删除的行再次出现在JTable中。 这可能会变得混乱,但希望有人能找出我错过了什么。帮助将会很感激,但不要,我的时间很少,不能完全大修我

  • 我正试图从数据库中删除一行,但得到以下错误

  • 我有一个jsp网页。我需要删除用户名从数据库当我按删除按钮从网页。我尝试了下面的代码,但是我不能删除名称,而是在用户名数据库中插入一个新行和一个空值。 unblockServlet.java: 受保护的void doPost(HttpServletRequest请求,HttpServletResponse响应)抛出ServletException,IOException{//TODO自动生成的方法

  • 我需要你帮我。我想在RecyclerView中通过SwipeToDelete删除数据库中的数据。 我已经有了一个从RecycleView中删除项目的Swipe类,我可以从该列表中删除项目,但不能从数据库中删除。 我尝试在NoteAdapater(回收器适配器)中调用数据库,并使用removeItem(int-position)方法删除所需的项,如下所示: 这是Main Active代码: 删除数据

  • 我想从数据库中删除一条特定的记录。