android——CRUD(在上一篇博客的基础上)

1、Person

package com.njupt.sqlite;public class Person {private Integer id;private String name;private Integer balance;public Integer getId() {return id;}public void setId(Integer id) {this.id = id;}public String getName() {return name;}public void setName(String name) {this.name = name;}public Integer getBalance() {return balance;}public void setBalance(Integer balance) {this.balance = balance;}@Overridepublic String toString() {return "Person [id=" + id + ", name=" + name + ", balance=" + balance+ "]";}public Person(Integer id, String name, Integer balance) {super();this.id = id;this.name = name;this.balance = balance;}public Person() {super();}}

2、PersonDao

package com.njupt.sqlite;import android.content.Context;import android.database.Cursor;import android.database.sqlite.SQLiteDatabase;public class PersonDao {private DBOpenHelper helper;public PersonDao(Context context){helper = new DBOpenHelper(context);}public void insert(Person p){SQLiteDatabase db = helper.getWritableDatabase();db.execSQL("insert into person1(name,balance) values(?,?)",new Object[]{p.getName(),p.getBalance()});    db.close();}public void delete(int id){ SQLiteDatabase db = helper.getWritableDatabase();    db.execSQL("delete from person1 where id = ?",new Object[]{id});    db.close();}public void update(Person p){SQLiteDatabase db = helper.getWritableDatabase();db.execSQL("update person1 set name = ? , balance = ? where id = ?", new Object[]{p.getName(),p.getBalance(),p.getId()});db.close();}public Person query(int id){SQLiteDatabase db = helper.getReadableDatabase();Cursor c = db.rawQuery("select name ,balance from person1 where id = ?", new String[]{id + ""});Person p = null;if(c.moveToNext()){String name = c.getString(0);int balance = c.getInt(1);p = new Person(id,name,balance);}return p;}       }

3、DBTest

以下附上测试类

package com.njupt.sqlite;import android.test.AndroidTestCase;public class DBTest extends AndroidTestCase{public void test1(){DBOpenHelper helper = new DBOpenHelper(getContext());helper.getWritableDatabase();}public void testInsert(){PersonDao dao = new PersonDao(getContext());Person p = new Person(3,"章泽天",45000);dao.insert(p);}public void testDelete(){PersonDao dao = new PersonDao(getContext());int id = 1;dao.delete(id);}public void testUpdate(){PersonDao dao = new PersonDao(getContext());Person p = new Person(2,"lss",40000);dao.update(p);}public void testQuery(){PersonDao dao = new PersonDao(getContext());Person p = dao.query(3);System.out.println(p);}}

4、最后我们可以在SQLiteExpert中看到相应的变化