Question

当我点击listview中的项目时，如何删除数据库中的数据？请给我一些代码。这是我在listview中选择项目的方法：

listview.setOnItemClickListener(new OnItemClickListener(){
        public void onItemClick(AdapterView adapterView, View convertView, int position, long id)
        {
            AlertDialog.Builder alertDialog = new AlertDialog.Builder(AndroidSpinnerFromSQLiteActivity.this);


            alertDialog.setTitle("Confirm Delete...");


            alertDialog.setMessage("Are you sure you want delete this?");


            alertDialog.setIcon(R.drawable.delete);


            alertDialog.setPositiveButton("YES",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog,int which) {


                        }
                    });

            alertDialog.setNegativeButton("NO",
                    new DialogInterface.OnClickListener() {
                        public void onClick(DialogInterface dialog, int which) {

                        }
                    });

            alertDialog.show();
            }
        });
    };

这是我的数据库类：

公共类DatabaseHandler扩展了SQLiteOpenHelper {

private static final int DATABASE_VERSION = 1;


private static final String DATABASE_NAME = "spinnerExample";


private static final String TABLE_LABELS = "labels";


private static final String KEY_ID = "id";
private static final String KEY_NAME = "name";
public DatabaseHandler(Context context) {
    super(context, DATABASE_NAME, null, DATABASE_VERSION);
}


@Override
public void onCreate(SQLiteDatabase db) {

    String CREATE_CATEGORIES_TABLE = "CREATE TABLE " + TABLE_LABELS + "("
            + KEY_ID + " INTEGER PRIMARY KEY," + KEY_NAME + " TEXT" +")";
    db.execSQL(CREATE_CATEGORIES_TABLE);
}


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

    db.execSQL("DROP TABLE IF EXISTS " + TABLE_LABELS);


    onCreate(db);
}


public void insertLabel(String label){
    SQLiteDatabase db = this.getWritableDatabase();

    ContentValues values = new ContentValues();
    values.put(KEY_NAME, label);


    db.insert(TABLE_LABELS, null, values);
    db.close(); 
}


public List<String> getAllLabels(){
    List<String> labels = new ArrayList<String>();


    String selectQuery = "SELECT  * FROM " + TABLE_LABELS;

    SQLiteDatabase db = this.getReadableDatabase();
    Cursor cursor = db.rawQuery(selectQuery, null);


    if (cursor.moveToFirst()) {
        do {
            labels.add(cursor.getString(1));
        } while (cursor.moveToNext());
    }


    cursor.close();
    db.close();


    return labels;
}

}

Answer 1

在ur数据库类代码中添加一个方法

如果你想删除全部原始表格，请使用

db.execSQL("DELETE from "+Table_Name);

其他你想删除表中的特定Raw

 db.delete(Table_Name, "Raw_Field_Name" + "='" + Raw_field_value+"'", null);

列表视图项目单击事件使用

    Listview lv;
//on create method 

     lv = (ListView) findViewById(R.id.list_contact_name);

              lv.setOnItemClickListener(new OnItemClickListener() 
                {

                    public void onItemClick(AdapterView<?> arg0, View v, int position,
                            long id) {

                      // call DELETE method here

                    }
                });

Answer 2

在Helper类中添加一个方法：

public boolean deleteData(String name)
{
    SQLiteDatabase db=getWritableDatabase();
    return db.delete(TABLE_NAME, KEY_NAME+"= ?", new String[]{name})>0;
}

使用标签名称调用此方法。您将在列表视图onItemClick上的OnItemClickListener方法中获得。

Answer 3

如果您想在删除数据后更新列表而不是使用。

adapter.notifyDataSetChanged（）; //其中adapter是您的Adapter对象。

从数据库中删除数据？

3 个答案: