在Android中删除SQLite中的行

Question

这可能是一个愚蠢的问题，但是我是SQLite的新手，我似乎无法弄清楚。我有了列1台KEY_ROWID，KEY_NAME，KAY_LATITUDE，和KEY_LONGITUDE。我希望用户能够选择一个并删除它；谁能给我一个开始的方向？我的问题是仅给定名称的行的实际删除。

相关代码：

public class BeaconDatabase {

    public static final String KEY_ROWID = "_id";

    public static final String KEY_NAME = "beacon_name";

    public static final String KEY_LATITUDE = "beacon_lat";

    public static final String KEY_LONGITUDE = "beacon_lon";

    private static final String DATABASE_NAME ="BeaconDatabase";

    private static final String DATABASE_TABLE ="beaconTable";

    private static final int DATABASE_VERSION = 1;

    private DbHelper helper;

    private final Context context;

    private SQLiteDatabase db;

    public BeaconDatabase(Context context) {

        this.context = context;

    }

    public BeaconDatabase open() {

        helper = new DbHelper(this.context);

        db = helper.getWritableDatabase();

        return this;

    }

    public void close() {

        helper.close();

    }

    public long createEntry(String name, Double lat, Double lon) {

        ContentValues cv = new ContentValues();

        cv.put(KEY_NAME, name);

        cv.put(KEY_LATITUDE, lat);

        cv.put(KEY_LONGITUDE, lon);

        return db.insert(DATABASE_TABLE, null, cv);

    }

    public void deleteEntry(long row) {

              // Deletes a row given its rowId, but I want to be able to pass

              // in the name of the KEY_NAME and have it delete that row.

              //db.delete(DATABASE_TABLE, KEY_ROWID + "=" + row, null);

    }

    public String getData() {

        String[] columns = { KEY_ROWID, KEY_NAME, KEY_LATITUDE, KEY_LONGITUDE };

        Cursor cursor = db.query(DATABASE_TABLE, columns, null, null, null, null, null);

        String result = "";

        int iRow = cursor.getColumnIndex(KEY_ROWID);

        int iName = cursor.getColumnIndex(KEY_NAME);

        int iLat = cursor.getColumnIndex(KEY_LATITUDE);

        int iLon = cursor.getColumnIndex(KEY_LONGITUDE);

Answer 1

您可以这样尝试： //---deletes a particular title---public boolean deleteTitle(String name) {    return db.delete(DATABASE_TABLE, KEY_NAME + "=" + name, null) > 0;}要么public boolean deleteTitle(String name) {    return db.delete(DATABASE_TABLE, KEY_NAME + "=?", new String[]{name}) > 0;}

Answer 2

那样尝试，可能会找到解决方案String table = "beaconTable";String whereClause = "_id=?";String[] whereArgs = new String[] { String.valueOf(row) };db.delete(table, whereClause, whereArgs);

Answer 3

最好也使用whereargs；db.delete("tablename","id=? and name=?",new String[]{"1","jack"});这就像使用以下命令：delete from tablename where id='1' and name ='jack'并且以这种方式使用delete函数是很好的，因为它可以删除sql注入。