使用SQLite数据库保存和处理数据
发布时间：2020-12-12 19:44:30 所属栏目：百科 来源：网络整理
导读：项目目的： 1.使用SQLite数据库保存数据 2.使用SQLite数据库的数据进行增删查改等操作。 3.学会使用SQLiteOpenHelper和SQLiteDatabase。 项目内容： 下面4图分别为主界面(1)，按添加进行添加操作(2)，点击listView的item进行修改操作(3)，长按item进行删除操
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项目目的： 1.使用SQLite数据库保存数据 2.使用SQLite数据库的数据进行增删查改等操作。 3.学会使用SQLiteOpenHelper和SQLiteDatabase。
项目内容： 下面4图分别为主界面(1)，按添加进行添加操作(2)，点击listView的item进行修改操作(3)，长按item进行删除操作(4)
项目结构为：
下面是代码： Member.java package android.ex08;
public class Member {
private long ID=-1;
private String name;
private String phone;
@Override
public String toString(){
String result="";
result+="ID: "+this.ID+",";
result+="姓名: "+this.name+",";
result+="号码: "+this.phone;
return result;
}
public long getID(){
return ID;
}
public String getName(){
return name;
}
public String getPhone(){
return phone;
}
public void setID(long newID){
ID=newID;
}
public void setName(String newName){
name=newName;
}
public void setPhone(String newPhone){
phone=newPhone;
}
}
MemberDAO.java package android.ex08;
import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class MemberDAO extends SQLiteOpenHelper {
private static final String DB_NAME="member.db";
private static final int DB_VERSION=1;
private static final String TABLE_NAME="member";
private static final String SQL_CREATE_TABLE="create table "+TABLE_NAME
+"(_id integer primary key autoincrement,"
+" name text not null,info text);";
public MemberDAO(Context context){
super(context,DB_NAME,null,DB_VERSION);
}
@Override
public void onCreate(SQLiteDatabase db) {
db.execSQL(SQL_CREATE_TABLE);
}
@Override
public void onUpgrade(SQLiteDatabase db,int oldVersion,int newVersion) {
//db.execSQL("DROP TABLE IF EXISTS "+TABLE_NAME);
//onCreate(db);
}
public long insert(Member entity){
SQLiteDatabase db=getWritableDatabase();
ContentValues values=new ContentValues();
values.put("name",entity.getName());
values.put("info",entity.getPhone());
long rid=db.insert(TABLE_NAME,values);
db.close();
return rid;
}
public long update(Member entity){
SQLiteDatabase db=getWritableDatabase();
String whereClause="_id=?";
String[] whereArgs={String.valueOf(entity.getID())};
ContentValues values=new ContentValues();
values.put("name",entity.getPhone());
long rows=db.update(TABLE_NAME,values,whereClause,whereArgs);
db.close();
return rows;
}
public long delete(long ID){
SQLiteDatabase db=getWritableDatabase();
long rows=db.delete(TABLE_NAME,"_id=?",new String[]{String.valueOf(ID)});
db.close();
return rows;
}
public long deleteAll(){
SQLiteDatabase db=getWritableDatabase();
long rows=db.delete(TABLE_NAME,null);
db.close();
return rows;
}
public Member[] getAllData(){
SQLiteDatabase db=getReadableDatabase();
Cursor result=db.query(TABLE_NAME,null);
return ConvertToMember(result);
}
private Member[] ConvertToMember(Cursor cursor){
int resultCounts=cursor.getCount();
if(resultCounts==0||!cursor.moveToFirst()){
return null;
}
Member[] members=new Member[resultCounts];
for(int i=0;i<resultCounts;i++){
members[i]=new Member();
members[i].setID(cursor.getInt(0));
members[i].setName(cursor.getString(cursor.getColumnIndex("name")));
members[i].setPhone(cursor.getString(cursor.getColumnIndex("info")));
cursor.moveToNext();
}
return members;
}
}
MainActivity.java package android.ex08;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.ContextMenu;
import android.view.ContextMenu.ContextMenuInfo;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.View.OnCreateContextMenuListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.ListView;
import android.widget.SimpleAdapter;
import android.widget.Toast;
public class MainActivity extends Activity {
public MemberDAO memberDAO=new MemberDAO(this);
public Member[] members;
private Button insert;
private ListView listView;
private List<Map<String,String>> arrayList=new ArrayList<Map<String,String>>();
private SimpleAdapter simpleAdapter;
private void setData(){
members=memberDAO.getAllData();
Map<String,String> map;
if(members==null){
return;
}
int count=members.length;
if(count!=0){
for(int i=0;i<count;i++){
map=new HashMap<String,String>();
map.put("name",members[i].getName());
map.put("info",members[i].getPhone());
arrayList.add(map);
}
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
insert=(Button)findViewById(R.id.button1);
listView=(ListView)findViewById(R.id.listView1);
setData();
simpleAdapter=new SimpleAdapter(this,arrayList,R.layout.list_item,new String[]{"name","info"},new int[]{R.id.listName,R.id.listInfo});
listView.setAdapter(simpleAdapter);
insert.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent intent=new Intent(MainActivity.this,SecondActivity.class);
startActivity(intent);
MainActivity.this.finish();
}
});
listView.setOnItemClickListener(new OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent,View view,int position,long id) {
Intent intent=new Intent(MainActivity.this,ThirdActivity.class);
Bundle bundle=new Bundle();
bundle.putLong("ID",id);
intent.putExtras(bundle);
startActivity(intent);
MainActivity.this.finish();
}
});
ItemOnLongClick();
}
public void ItemOnLongClick() {
//注：setOnCreateContextMenuListener是与下面onContextItemSelected配套使用的
listView.setOnCreateContextMenuListener(new OnCreateContextMenuListener() {
@Override
public void onCreateContextMenu(ContextMenu menu,View v,ContextMenuInfo menuInfo) {
menu.add(0,"删除");//设置弹出菜单的条目
}
});
}
public boolean onContextItemSelected(MenuItem item) {
AdapterView.AdapterContextMenuInfo info = (AdapterView.AdapterContextMenuInfo) item.getMenuInfo();
int MID = (int) info.id; //MID为listView中的数据序号，从0开始
switch (item.getItemId()) {
case 0:
// 删除操作,修改数据库
members=memberDAO.getAllData();
long _id=members[MID].getID();
memberDAO.delete(_id);
arrayList.remove(MID); //从链表中把该item移除
simpleAdapter.notifyDataSetChanged(); //更新适配器
Toast.makeText(MainActivity.this,"删除成功",Toast.LENGTH_SHORT).show();
break;
default:
break;
}
return super.onContextItemSelected(item);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main,menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button,so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
SecondActivity.java package android.ex08;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.view.View.OnClickListener;
//处理insert操作
public class SecondActivity extends Activity {
public MemberDAO memberDAO=new MemberDAO(this);
private EditText textName,textPhone;
private Button confirm,cancel;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.insert_mem);
textName=(EditText)findViewById(R.id.insert_editText1);
textPhone=(EditText)findViewById(R.id.insert_editText2);
confirm=(Button)findViewById(R.id.insert_button1);
cancel=(Button)findViewById(R.id.insert_button2);
confirm.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Member member=new Member();
member.setName(textName.getText().toString());
member.setPhone(textPhone.getText().toString());
memberDAO.insert(member);
Intent intent=new Intent(SecondActivity.this,MainActivity.class);
startActivity(intent);
SecondActivity.this.finish();
}
});
cancel.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent intent=new Intent(SecondActivity.this,MainActivity.class);
startActivity(intent);
SecondActivity.this.finish();
}
});
}
}
ThirdActivity.java package android.ex08;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.EditText;
//处理update操作
public class ThirdActivity extends Activity {
public MemberDAO memberDAO=new MemberDAO(this);
private EditText textName,cancel;
private long bundle_ID;
Member[] members=null;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.update_mem);
textName=(EditText)findViewById(R.id.update_editText1);
textPhone=(EditText)findViewById(R.id.update_editText2);
confirm=(Button)findViewById(R.id.update_button1);
cancel=(Button)findViewById(R.id.update_button2);
Bundle bundle=ThirdActivity.this.getIntent().getExtras();
bundle_ID=bundle.getLong("ID");
members=memberDAO.getAllData();
textName.setText(members[(int)bundle_ID].getName());
textPhone.setText(members[(int)bundle_ID].getPhone());
confirm.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
members[(int)bundle_ID].setName(textName.getText().toString());
members[(int)bundle_ID].setPhone(textPhone.getText().toString());
memberDAO.update(members[(int)bundle_ID]);
Intent intent=new Intent(ThirdActivity.this,MainActivity.class);
startActivity(intent);
ThirdActivity.this.finish();
}
});
cancel.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
Intent intent=new Intent(ThirdActivity.this,MainActivity.class);
startActivity(intent);
ThirdActivity.this.finish();
}
});
}
}
activity_main.xml <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="android.ex08.MainActivity" >
<TextView
android:id="@+id/textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="@string/memberList"
android:textSize="22sp" />
<Button
android:id="@+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="@string/insert" />
<ListView
android:id="@+id/listView1"
android:layout_width="match_parent"
android:layout_height="wrap_content" >
</ListView>
</LinearLayout>
insert_mem.xml <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin" >
<TextView
android:id="@+id/insert_textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="@string/insertMember"
android:textSize="22sp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/insert_textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="18sp"
android:text="@string/name" />
<EditText
android:id="@+id/insert_editText1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:hint="@string/enterName">
<requestFocus />
</EditText>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/insert_textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="18sp"
android:text="@string/phone"/>
<EditText
android:id="@+id/insert_editText2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:hint="@string/enterPhone"
android:inputType="phone" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingLeft="50dp" >
<Button
android:id="@+id/insert_button1"
android:layout_width="80dp"
android:layout_height="wrap_content"
android:text="@string/confirm"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="right"
android:layout_marginRight="50dp">
<Button
android:id="@+id/insert_button2"
android:layout_width="80dp"
android:layout_height="wrap_content"
android:text="@string/cancel" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
update_mem.xml <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin" >
<TextView
android:id="@+id/update_textView1"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:text="@string/updateMember"
android:textSize="22sp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/update_textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="18sp"
android:text="@string/name" />
<EditText
android:id="@+id/update_editText1"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:hint="@string/enterName">
<requestFocus />
</EditText>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content" >
<TextView
android:id="@+id/update_textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textSize="18sp"
android:text="@string/phone"/>
<EditText
android:id="@+id/update_editText2"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:ems="10"
android:hint="@string/enterPhone"
android:inputType="phone" />
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingLeft="50dp" >
<Button
android:id="@+id/update_button1"
android:layout_width="80dp"
android:layout_height="wrap_content"
android:text="@string/confirm"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="right"
android:layout_marginRight="50dp">
<Button
android:id="@+id/update_button2"
android:layout_width="80dp"
android:layout_height="wrap_content"
android:text="@string/cancel" />
</LinearLayout>
</LinearLayout>
</LinearLayout>
list_item.xml <?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin" >
<TextView
android:id="@+id/listName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/name"
android:textSize="22sp"/>
<TextView
android:id="@+id/listInfo"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/phone"/>
</LinearLayout>
strings.xml <?xml version="1.0" encoding="utf-8"?>
<resources>
<string name="app_name">EX08</string>
<string name="app_name1">SecondActivity</string>
<string name="app_name2">ThirdActivity</string>
<string name="action_settings">Settings</string>
<string name="insert">添加</string>
<string name="memberList">成员列表</string>
<string name="insertMember">添加新成员</string>
<string name="updateMember">修改成员</string>
<string name="name">姓名:</string>
<string name="phone">号码:</string>
<string name="confirm">确定</string>
<string name="cancel">取消</string>
<string name="enterName">请输入姓名</string>
<string name="enterPhone">请输入号码</string>
</resources>
AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="android.ex08"
android:versionCode="1"
android:versionName="1.0" >
<uses-sdk
android:minSdkVersion="15"
android:targetSdkVersion="19" />
<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".MainActivity"
android:label="@string/app_name" >
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<activity android:name=".SecondActivity"
android:label="@string/app_name1">
</activity>
<activity android:name=".ThirdActivity"
android:label="@string/app_name2">
</activity>
</application>
</manifest>
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