如何使用 SimpleCursorAdapter 获取 _ID

Question

到目前为止，我得到了这个

  db = new MYDBHelper(this);
    constantsCursor = db.getReadableDatabase().rawQuery(
            "SELECT _ID, title, value " + "FROM constants ORDER BY title", null);
ListAdapter adapter = new SimpleCursorAdapter(this, R.layout.item, constantsCursor, new String[] { DBHelperMen2.TITLE, DBHelperMen2.VALUE }, new int[] {R.id.item_name, R.id.item_points });
listata = (ListView) findViewById(R.id.listView1);
listata.setAdapter(adapter);

但我还有一个名为 item_number 的字段。我这个字段我要写_ID号

我该怎么做？

new SimpleCursorAdapter(this, R.layout.item, constantsCursor, new String[] { **???** ,MYDBHelper.TITLE, MYDBHelper.VALUE }, new int[] {**R.id.item_number** , R.id.item_name, R.id.item_points });

这里是 MYDBHelper

public class MYDBHelper extends SQLiteOpenHelper {
    private static final String DATABASE_NAME = "db";
    static final String TITLE = "title";
    static final String VALUE = "value";

    public MYDBHelper(Context context) {
        super(context, DATABASE_NAME, null, 1);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {

        db.execSQL("CREATE TABLE constants (_id INTEGER PRIMARY KEY AUTOINCREMENT, title TEXT, value TEXT);");
    }



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

Answer 1

只需这样做：

ListAdapter adapter = new SimpleCursorAdapter(this, R.layout.item, constantsCursor, new String[] { DBHelperMen2.ID, DBHelperMen2.TITLE, DBHelperMen2.VALUE }, new int[] {R.id.item_number, R.id.item_name, R.id.item_points });

在 DBHelperMen2.ID 中，ID 是您的数据库中列的名称

这段代码应该可以工作：

public class MYDBHelper extends SQLiteOpenHelper {
private static final String DATABASE_NAME = "db";

static final String TABLE_NAME = "constants";
static final String ID = "_id";

static final String TITLE = "title";
static final String VALUE = "value";

public MYDBHelper(Context context) {
    super(context, DATABASE_NAME, null, 1);
}

@Override
public void onCreate(SQLiteDatabase db) {

    db.execSQL("CREATE TABLE "+ TABLE_NAME + "(" + ID + " INTEGER PRIMARY KEY AUTOINCREMENT, " + TITLE + " TEXT, " + VALUE + " TEXT);");
}



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

}