Java 在Sqlite android中从数据库中删除数据
这是我在SqliteDatabase类中的delete函数Java 在Sqlite android中从数据库中删除数据,java,android,android-sqlite,Java,Android,Android Sqlite,这是我在SqliteDatabase类中的delete函数 public void deleteContact(Employee contact) { SQLiteDatabase db = this.getWritableDatabase(); db.delete(TABLE_EMployee, KEY_ID + " = ?", new String[] { String.valueOf(con
public void deleteContact(Employee contact) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_EMployee, KEY_ID + " = ?",
new String[] { String.valueOf(contact.get_id()) });
db.close();
}
员工类别:
public class Employee {
private int _id;
private String _name;
private String _email;
public Employee() {
// TODO Auto-generated constructor stub
}
public Employee(int id, String name, String email) {
this._id = id;
this._name = name;
this._email = email;
}
public Employee(String name, String email) {
this._name = name;
this._email = email;
}
public int get_id() {
return _id;
}
public void set_id(int _id) {
this._id = _id;
}
public String get_name() {
return _name;
}
public void set_name(String _name) {
this._name = _name;
}
public String get_email() {
return _email;
}
public void set_email(String _email) {
this._email = _email;
}
}
MainActivity Class:
public class MainActivity extends Activity {
MySqliteDatabase db = new MySqliteDatabase(this);
EditText nametext;
EditText emailtext;
Button btn;
public List<Employee> list1 = new ArrayList<Employee>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
nametext = (EditText) findViewById(R.id.editText1);
emailtext = (EditText) findViewById(R.id.editText2);
btn = (Button) findViewById(R.id.button1);
ListView list = (ListView) findViewById(R.id.listView1);
btn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
String name = nametext.getText().toString();
String email = emailtext.getText().toString();
db.addEmployee(new Employee(name, email));
Toast.makeText(getApplicationContext(), "SucessfullyInseter",
1000).show();
}
});
list.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,
long arg3) {
// TODO Auto-generated method stub
Toast.makeText(getApplicationContext(), arg2 + "clicke", 1000)
.show();
}
});
list.setOnItemLongClickListener(new OnItemLongClickListener() {
@Override
public boolean onItemLongClick(AdapterView<?> arg0, View arg1,
int arg2, long arg3) {
// TODO Auto-generated method stub
Employee emp = new Employee();
db.deleteContact(emp);
return false;
}
});
}
@Override
protected void onStart() {
// TODO Auto-generated method stub
super.onStart();
List<Employee> contacts = db.getAllContacts();
for (Employee cn : contacts) {
String log = "Id: " + cn.get_id() + " ,Name: " + cn.get_name()
+ " ,Phone: " + cn.get_email();
// Writing Contacts to log
Log.d("Name: ", log);
}
ListView list = (ListView) findViewById(R.id.listView1);
ContanctAdapter objAdapter = new ContanctAdapter(MainActivity.this,
R.layout.alluser_row, contacts);
list.setAdapter(objAdapter);
}
}
公共类员工{
私人内部id;
私有字符串\u名称;
私人字符串\u电子邮件;
公职人员(){
//TODO自动生成的构造函数存根
}
公共雇员(整数id、字符串名称、字符串电子邮件){
这个。_id=id;
这个。_name=name;
这个。_email=电子邮件;
}
公共雇员(字符串名称、字符串电子邮件){
这个。_name=name;
这个。_email=电子邮件;
}
public int get_id(){
返回_id;
}
公共无效集\u id(int\u id){
这个。_id=_id;
}
公共字符串get_name(){
返回_name;
}
公共无效集\u名称(字符串\u名称){
这个。_name=_name;
}
公共字符串get_email(){
返回电子邮件;
}
公共无效设置\u电子邮件(字符串\u电子邮件){
这个.\u email=\u email;
}
}
主要活动类别:
公共类MainActivity扩展了活动{
MySqliteDatabase db=新的MySqliteDatabase(this);
编辑文本名称文本;
编辑文本电子邮件文本;
按钮btn;
public List list1=new ArrayList();
@凌驾
创建时受保护的void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
nametext=(EditText)findViewById(R.id.editText1);
emailtext=(EditText)findViewById(R.id.editText2);
btn=(按钮)findViewById(R.id.button1);
ListView列表=(ListView)findViewById(R.id.listView1);
btn.setOnClickListener(新的OnClickListener(){
@凌驾
公共void onClick(视图v){
//TODO自动生成的方法存根
String name=nametext.getText().toString();
字符串email=emailtext.getText().toString();
db.新增员工(新员工(姓名、电子邮件));
Toast.makeText(getApplicationContext(),“SuccessFullyInSeter”,
1000)show();
}
});
list.setOnItemClickListener(新的OnItemClickListener(){
@凌驾
公共链接(AdapterView arg0、视图arg1、内部arg2、,
长arg3){
//TODO自动生成的方法存根
Toast.makeText(getApplicationContext(),arg2+“clicke”,1000)
.show();
}
});
list.setOnItemLongClickListener(新的OnItemLongClickListener(){
@凌驾
长单击(AdapterView arg0、视图arg1、,
整数arg2,长arg3){
//TODO自动生成的方法存根
员工emp=新员工();
db.deleteContact(emp);
返回false;
}
});
}
@凌驾
受保护的void onStart(){
//TODO自动生成的方法存根
super.onStart();
List contacts=db.getAllContacts();
对于(员工cn:联系人){
String log=“Id:”+cn.get_Id()+”,Name:“+cn.get_Name()
+,电话:“+cn.get_email();
//将联系人写入日志
Log.d(“名称:”,Log);
}
ListView列表=(ListView)findViewById(R.id.listView1);
ContanctAdapter objAdapter=新ContanctAdapter(main activity.this,
R.layout.alluser_行,触点);
列表.setAdapter(objAdapter);
}
}
当我需要longitemclick功能时,我想删除特定项目的联系人,但我无法删除。请告诉我如何耗尽联系人。像这样使用
//删除
public void deleteid(Employee contact) {
SQLiteDatabase db = this.getWritableDatabase();
db.delete(TABLE_EMployee, KEY_ID + " = ?",
new String[] { String.valueOf(contact.getID()) });
db.close();
}
您应该像这样调用该方法
Employee emp = new Employee();
emp.setId(yourid);
db.deleteContact(emp);
您遇到了什么错误?但无法删除列表数据您是否检查了数据库,如果它实际上已被删除,但未从列表中删除?是的,我认为我在这里犯了错误。请告诉我如何应用Employee emp=new Employee();db.deleteContact(emp);返回false;删除sql lite上的数据时,listview不会影响,从db数据库中删除时,应删除列表中的行。在Mainactivity中,从listview中删除数据时,不应删除数据class@user3432979我知道它将在databaseHandler类中,对吗?是的,请帮助我,我认为我在这里犯了错误雇员emp=新雇员(); db.deleteContact(emp);返回false;我将如何设置它我将把listview的位置值设置为?@user3432979:不明白吗?