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Android 如何从SQLitedatabase更新和删除行?_Android_Sqlite - Fatal编程技术网

Android 如何从SQLitedatabase更新和删除行?

Android 如何从SQLitedatabase更新和删除行?,android,sqlite,Android,Sqlite,我是android开发新手,当我在首页listview开发记事本应用程序时,我想更新并删除listview中的一行: public void Update(String txt) { ContentValues upateValues = createContentValues(txt); db.update(table_name, upateValues, row + "="+ "a", null); Toast.makeText(this, "Record U

我是android开发新手,当我在首页
listview
开发记事本应用程序时,我想更新并删除
listview
中的一行:

public void Update(String txt)
    {
    ContentValues upateValues = createContentValues(txt);
    db.update(table_name, upateValues, row + "="+ "a", null);
    Toast.makeText(this, "Record Updated", Toast.LENGTH_SHORT).show();
    }

public void Delete()
    {
    db.delete(table_name, "row" +"="+"jmj", null);
    Toast.makeText(this, "Record Deleted", Toast.LENGTH_SHORT).show();
    //Display();
    }
对于更新和删除操作,此查询正确吗?

您有两个(主要)选项来执行此操作:

1) 像在任何其他数据库引擎中一样使用rawQuery和write update/delete

db.rawQuery("UPDATE table_name SET column1=value, column2=value2 WHERE some_column=some_value")
2) 使用“helper”方法并按如下方式执行: 更新:

删除:

db.delete(TABLE, ID + " =? ", new String[] { intId });
别忘了告诉listview数据集已更改。如何做到这一点取决于您为ListView使用的适配器。我想您不会使用ContentProvider/Loader这么简单的适配器。notifyDatasetChanged()应该会有所帮助

db.delete(TABLE, ID + " =? ", new String[] { intId });