Android sqlite 数据库查询，插入，删除，更新demo<第5章>---删除

根据第2章，删除数据库中的数据，实际调用SQLiteDatabase的delete()方法

布局文件：delete_userdata_dialog.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
     android:layout_width="fill_parent"
     android:layout_height="fill_parent"
android:padding="10px"
>


     <LinearLayout
         android:id="@+id/linearlayout_input_userid"
         android:layout_width="fill_parent"
         android:layout_height="wrap_content"
         android:orientation="horizontal" >

         <TextView
             android:id="@+id/userid"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="input id:" />

         <EditText
             android:id="@+id/input_useid"
             android:layout_width="fill_parent"
             android:layout_height="wrap_content"
             android:numeric="integer" />
     </LinearLayout>
     
     <Button 
         android:id="@+id/input_userid_commit"
         android:layout_below="@id/linearlayout_input_userid"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:layout_alignParentRight="true"
         android:text="commit"/>

 </RelativeLayout>

并在AndroidManifest.xml配置文件，修改theme = “@android:style/Theme.Dialog”

Activity： 上代码：

package com.example.listviewdatabase;

 import android.app.Activity;
 import android.database.sqlite.SQLiteDatabase;
 import android.os.Bundle;
 import android.view.View;
 import android.view.View.OnClickListener;
 import android.widget.Button;
 import android.widget.EditText;

 public class DeleteUserDataDialog extends Activity {

private Button commit = null;
private EditText input_userid = null;

@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
setContentView(R.layout.delete_userdata_dialog);

commit = (Button) findViewById(R.id.input_userid_commit);
commit.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
// TODO Auto-generated method stub
input_userid = (EditText) findViewById(R.id.input_useid);
int user_id = Integer.parseInt(input_userid.getText()
.toString());

DataBaseHelper dbh = new DataBaseHelper(
DeleteUserDataDialog.this, null);
SQLiteDatabase db = dbh.getWritableDatabase();

dbh.deleteUserDataToDataBase(db, user_id);
db.close();
dbh.close();
DeleteUserDataDialog.this.finish();
}
});
}
 }

其中DataBaseHelper中delete()函数

public void deleteUserDataToDataBase(SQLiteDatabase db,int id){

Log.i(TAG, "id = "+id);
String[] args = {String.valueOf(id)};

db.delete(TABLE_NAME, "_id=?", args);   //  _id是表中列，args不能写成 new String[]{"id"}
 }

此文章是本人学习笔记，能力有限，相互学习，欢迎点评，谢谢...