看看我用来制作一个示例项目的代码。只要执行和使用SQLitedatabase,它就会为您提供一切您需要知道的信息。它回答你的两个问题。 该示例将书中用户的书名,作者,isbn编号,评分和状态插入到数据库中,允许将数据更新删除并逐个提取。
public class DbAdapter {
private static final String DATABASE_NAME = " nba";
private static final String DATABASE_TABLE = "bookList";
private static final int DATABASE_VERSION = 1;
private static String TAG = "Upgrading Database!";
public static final String KEY_BOOK = "book";
public static final String KEY_AUTHOR = "author";
public static final String KEY_ISBN = "isbn";
public static final String KEY_ROWID = "_id";
public static final String KEY_RATING = "rating";
public static final String KEY_STATUS = "status";
private DatabaseHelper mDbHelper;
private SQLiteDatabase mDb;
private static final String DATABASE_CREATE =
" create table " + DATABASE_TABLE + " ("
+ KEY_ROWID + " integer primary key autoincrement, "
+ KEY_AUTHOR + " text not null, "
+ KEY_BOOK + " text not null, "
+ KEY_RATING + " text not null, "
+ KEY_STATUS + " text not null, "
+ KEY_ISBN + " text not null); ";
private final Context mCtx;
public DbAdapter (Context ctx){
this.mCtx = ctx;
}
private static class DatabaseHelper extends SQLiteOpenHelper{
DatabaseHelper(Context context){
super(context, DATABASE_NAME, null, DATABASE_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(DATABASE_CREATE);
}
@Override
public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
db.execSQL("ALTER TABLE bookList ADD COLUMN String status");
}
}
public DbAdapter open() throws SQLException{
mDbHelper = new DatabaseHelper(mCtx);
mDb = mDbHelper.getWritableDatabase();
return this;
}
public void close(){
mDbHelper.close();
}
public long createBook(String book, String author, String isbn, float rating, String status){
ContentValues initialValues = new ContentValues();
initialValues.put(KEY_BOOK, book);
initialValues.put(KEY_AUTHOR, author);
initialValues.put(KEY_ISBN, isbn);
initialValues.put(KEY_RATING, rating);
initialValues.put(KEY_STATUS, status);
return mDb.insert(DATABASE_TABLE, null, initialValues);
}
public boolean deleteBook(long rowId){
return mDb.delete(DATABASE_TABLE, KEY_ROWID + "=" + rowId, null) > 0;
}
public Cursor fetchAllBooks(){
return mDb.query(DATABASE_TABLE, new String[]{KEY_BOOK, KEY_ISBN,KEY_AUTHOR,KEY_ROWID, KEY_RATING, KEY_STATUS}, null, null, null, null, null);
}
public Cursor fetchBook(long rowId) throws SQLException{
Cursor mCursor =
mDb.query(DATABASE_TABLE, new String[]{KEY_BOOK, KEY_AUTHOR,KEY_ROWID, KEY_ISBN, KEY_RATING, KEY_STATUS}, KEY_ROWID + "=" +
rowId, null, null, null, null);
if(mCursor != null){
mCursor.moveToFirst();
}
return mCursor;
}
public boolean updateBook(long rowId, String book, String author, String isbn, float rating, String status){
ContentValues args = new ContentValues();
args.put(KEY_BOOK, book);
args.put(KEY_AUTHOR, author);
args.put(KEY_ISBN, isbn);
args.put(KEY_RATING, rating);
args.put(KEY_STATUS, status);
return mDb.update(DATABASE_TABLE, args, KEY_ROWID + "=" + rowId, null)> 0;
}
}
感谢您的回答。我将使用Cursor类来返回数据。但我不知道android是否有更好的类来返回数据?像DataSet一样,更有用一个? – ahmet 2011-12-31 19:46:40
光标是大多数开发人员使用的。在我4年的发展过程中,我没有看到任何人使用其他任何东西。并不是说它无法完成。 – 2011-12-31 19:53:47
然后确定。这意味着它对我也很有用。感谢您的回答。 – ahmet 2011-12-31 19:57:51