package com.example.dbtest.dbHelper;

import android.content.Context;

import android.database.sqlite.SQLiteDatabase;

import android.database.sqlite.SQLiteOpenHelper;

//继承SQLiteOpenHelper类

public class DbOpenHelper extends SQLiteOpenHelper {

    public DbOpenHelper(Context context) {

        //Context 上下文

        //name 数据库名

        //CursorFactory 游标工厂模式 当为null时 使用默认值

        //version 数据库版本 版本号从1开始

        super(context, "test.db", null, 1);

    }

    /**

     * 第一次访问数据库 执行方法

     * */

    @Override

    public void onCreate(SQLiteDatabase db) {

        //创建表结构

        String sql = "create table person(id integer primary key autoincrement,name varchar(20),age int,phone varchar(11))";

        db.execSQL(sql);

    }

    @Override

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

    }

}

package com.example.dbtest.domain;

public class Person {

    private int id;

    private String name;

    private int age;

    private String phone;

    public Person(){}

    public Person(int id, String name, int age, String phone) {

        super();

        this.id = id;

        this.name = name;

        this.age = age;

        this.phone = phone;

    }

    public int getId() {

        return id;

    }

    public void setId(int id) {

        this.id = id;

    }

    public String getName() {

        return name;

    }

    public void setName(String name) {

        this.name = name;

    }

    public int getAge() {

        return age;

    }

    public void setAge(int age) {

        this.age = age;

    }

    public String getPhone() {

        return phone;

    }

    public void setPhone(String phone) {

        this.phone = phone;

    }

    @Override

    public String toString() {

        return "个人信息[id=" + id + ", name=" + name + ", age=" + age

                + ", phone=" + phone + "]";

    }

}

package com.example.dbtest.dao;

import java.util.ArrayList;

import java.util.List;

import android.content.Context;

import android.database.Cursor;

import android.database.sqlite.SQLiteDatabase;

import com.example.dbtest.dbHelper.DbOpenHelper;

import com.example.dbtest.domain.Person;

public class PersonDao {

    private DbOpenHelper helper;

    public PersonDao(Context context)

    {

        helper = new DbOpenHelper(context);

    }

    //添加一条记录

    public void add(Person p)

    {

        SQLiteDatabase db = helper.getWritableDatabase();

        String sql = "insert into person(name,age,phone) values(?,?,?)";

        db.execSQL(sql, new Object[]{p.getName(),p.getAge(),p.getPhone()});

    }

    //修改一条记录

    public void update(Person p)

    {

        SQLiteDatabase db = helper.getWritableDatabase();

        String sql = "update person set age=?,phone=? where name=?";

        db.execSQL(sql, new Object[]{p.getAge(),p.getPhone(),p.getName()});

    }

    //删除一条记录

    public void delete(String name)

    {

        SQLiteDatabase db = helper.getWritableDatabase();

        String sql = "delete from person where name=?";

        db.execSQL(sql,new Object[]{name});

    }

    public Person findByName(String name)

    {

        SQLiteDatabase db = helper.getReadableDatabase();

        String sql = "select * from person where name=?";

        Cursor cursor = db.rawQuery(sql, new String[]{name});

        Person p = null;

        while(cursor.moveToNext())

        {

            int id = cursor.getInt(cursor.getColumnIndex("id"));

            String phone = cursor.getString(cursor.getColumnIndex("phone"));

            int age = cursor.getInt(cursor.getColumnIndex("age"));

            p = new Person(id,name,age,phone);

        }

        return p;

    }

    public List<Person> findAll(String name)

    {

        SQLiteDatabase db = helper.getReadableDatabase();

        String sql = "select * from person where name=?";

        Cursor cursor = db.rawQuery(sql, new String[]{name});

        List<Person> list = new ArrayList();

        while(cursor.moveToNext())

        {

            int id = cursor.getInt(cursor.getColumnIndex("id"));

            String phone = cursor.getString(cursor.getColumnIndex("phone"));

            int age = cursor.getInt(cursor.getColumnIndex("age"));

            Person p = new Person(id,name,age,phone);

            list.add(p);

        }

        return list;

    }

}

<RelativeLayout 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: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="com.example.dbtest.MainActivity" >

    <Button

        android:id="@+id/btn_createDB"

        android:onClick="createDB"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:text="创建数据库" />

    <TextView

        android:id="@+id/textView1"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignLeft="@+id/btn_createDB"

        android:layout_below="@+id/btn_createDB"

        android:text="姓名" />

    <EditText

        android:id="@+id/et_name"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignLeft="@+id/textView1"

        android:layout_below="@+id/textView1"

        android:layout_marginLeft="21dp"

        android:layout_marginTop="24dp"

        android:ems="10"

    />

  <TextView

        android:id="@+id/textView2"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignLeft="@+id/btn_createDB"

        android:layout_below="@+id/et_name"

        android:text="电话" />

    <EditText

        android:id="@+id/et_phone"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_alignLeft="@+id/textView2"

        android:layout_below="@+id/textView2"

        android:layout_marginLeft="21dp"

        android:layout_marginTop="24dp"

        android:ems="10"

    />

<Button

        android:id="@+id/btn_save"

        android:onClick="save"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_below="@+id/et_phone"

        android:text="保存" />

<Button

        android:id="@+id/btn_update"

        android:onClick="update"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_below="@+id/btn_save"

        android:text="修改" />

<Button

        android:id="@+id/btn_find"

        android:onClick="findOne"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_below="@+id/btn_update"

        android:text="查询" />

<Button

        android:id="@+id/btn_delete"

        android:onClick="delete"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_below="@+id/btn_find"

        android:text="删除" />

</RelativeLayout>

package com.example.dbtest;

import android.os.Bundle;

import android.support.v7.app.ActionBarActivity;

import android.text.TextUtils;

import android.view.Menu;

import android.view.MenuItem;

import android.view.View;

import android.widget.EditText;

import android.widget.Toast;

import com.example.dbtest.dao.PersonDao;

import com.example.dbtest.dbHelper.DbOpenHelper;

import com.example.dbtest.domain.Person;

public class MainActivity extends ActionBarActivity {

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

    }

    public void createDB(View v)

    {

        DbOpenHelper db = new DbOpenHelper(this);

        //该句才真正创建数据库

        db.getWritableDatabase();

        Toast.makeText(this, "数据库创建成功", 0).show();

    }

    public void save(View v)

    {

        EditText nameText = (EditText)this.findViewById(R.id.et_name);

        EditText phoneText = (EditText)this.findViewById(R.id.et_phone);

        String name = nameText.getText().toString();

        String phone = phoneText.getText().toString();

        if(TextUtils.isEmpty(name) || TextUtils.isEmpty(phone))

        {

            Toast.makeText(this, "姓名和电话不能为空", 0).show();

            return;

        }

        PersonDao dao = new PersonDao(this);

        Person p = new Person();

        p.setName(name);

        p.setPhone(phone);

        dao.add(p);

        Toast.makeText(this, "保存成功", 0).show();

    }

    public void update(View v)

    {

        EditText nameText = (EditText)this.findViewById(R.id.et_name);

        EditText phoneText = (EditText)this.findViewById(R.id.et_phone);

        String name = nameText.getText().toString();

        String phone = phoneText.getText().toString();

        PersonDao dao = new PersonDao(this);

        Person p = new Person();

        p.setName(name);

        p.setPhone(phone);

        dao.update(p);

        Toast.makeText(this, "修改成功", 0).show();

    }

    public void delete(View v)

    {

        EditText nameText = (EditText)this.findViewById(R.id.et_name);

        EditText phoneText = (EditText)this.findViewById(R.id.et_phone);

        String name = nameText.getText().toString();

        String phone = phoneText.getText().toString();

        PersonDao dao = new PersonDao(this);

        dao.delete(name);

        Toast.makeText(this, "删除成功", 0).show();

    }

}