Android开发之使用SQLite存储数据的方法分析

package org.lxh.service;
import android.content.Context;
import android.database.sqlite.sqliteDatabase;
import android.database.sqlite.sqliteDatabase.cursorFactory;
import android.database.sqlite.sqliteOpenHelper;
import android.database.sqlite.sqliteQueryBuilder;
public class DBservice extends sqliteOpenHelper { //使用sqliteOpenHelper创建数据库
  public DBservice(Context context) {
    super(context,"mldn.db",null,1);
  }
  public void onCreate(sqliteDatabase db) {
    @R_607_10495@ng sql="create table student(userid integer priMary key autoincrement,username varchar(30))";  //生成数据库表的sql
    db.execsql(sql); //生成表
  }
  public void onUpgrade(sqliteDatabase db,int oldVersion,int newVersion) {
  }
}

package org.lxh.service;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.lxh.vo.student;
import android.content.Context;
import android.database.cursor;
import android.database.sqlite.sqliteDatabase;
public class studentservice {
  private DBservice db;
  public studentservice(Context context){ //构造方法实例化DBservice
    db=new DBservice(context);
  }
  public void savePerson(List<student> stu){
    @R_607_10495@ng sql="insert into student(userName) values(?)";
    sqliteDatabase database=db.getWritableDatabase(); //使用getWritableDatabase取得sqliteDatabase
    Iterator<student> it=stu.iterator();
    while(it.hasNext()){
      student student=it.next();
      database.execsql(sql,new Object[]{student.getUsername()}); //执行插入
    }
  }
  public void delete(int userid){
    @R_607_10495@ng sql="delete from student where userid=?";
    sqliteDatabase database=db.getWritableDatabase();
    database.execsql(sql,new Object[]{@R_607_10495@ng.valueOf(userid)});
  }
  public List<student> fiandAll(){
    List<student> all=new ArrayList<student>();
    @R_607_10495@ng sql="SELEct * from student";
    sqliteDatabase database=db.getReadableDatabase(); //使用getReadableDatabase取得sqliteDatabase
    cursor cursor=database.rawQuery(sql,null); //得到游标,类似resultset
    student stu;
    while(cursor.moveToNext()){ //移动游标
      int id=cursor.geTint(cursor.getcolumnIndex("userid"));
      @R_607_10495@ng name=cursor.get@R_607_10495@ng(cursor.getcolumnIndex("username"));
      stu=new student();
      stu.setUserid(id);
      stu.setUsername(Name);
      all.add(stu);
    }
    cursor.close(); //关闭游标
    return all;
  }
  public int getCount(){
    @R_607_10495@ng sql="SELEct count(*) from student";
    sqliteDatabase database=db.getReadableDatabase();
    cursor cursor=database.rawQuery(sql,null);
    cursor.moveToFirst();
    return cursor.geTint(0);
  }
}

package org.lxh.db;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import org.lxh.service.DBservice;
import org.lxh.service.studentservice;
import org.lxh.vo.student;
import android.test.Android@R_616_8932@ase;
import android.util.Log;
public class Test extends Android@R_616_8932@ase{
  public void testSave(){
    DBservice db=new DBservice(this.getContext());
    db.getWritableDatabase();
  }
  public void testSavestudent(){
    studentservice service=new studentservice(this.getContext());
    student stu=null;
    List<student> stus=new ArrayList<student>();
    for(int i=0;i<10;i++){
      stu = new student();
      stu.setUsername("陈亚峰"+i);
      stus.add(stu);
    }
    service.savePerson(stus);
  }
  public void delete(){
    studentservice service=new studentservice(this.getContext());
    service.delete(11);
  }
  public void findAll(){
    studentservice service=new studentservice(this.getContext());
    List<student> all=service.fiandAll();
    Iterator<student> it=all.iterator();
    while(it.hasNext()){
      student stu=it.next();
      Log.i("Test","id:"+stu.getUserid()+","+"username"+stu.getUsername());
    }
  }
  public void findRows(){
    studentservice service=new studentservice(this.getContext());
    Log.i("Test",@R_607_10495@ng.valueOf(service.getCount()));
  }
}