sqlite增刪改查（二）

使用sqlite內建的crud方法操作資料庫，不贊成使用，因為效率沒直接操作sql語句高

所以只把例子貼出來

OtherPersonService

package com.tjp.service;

import java.util.ArrayList;
import java.util.List;

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;

import com.tjp.model.Person;

public class OtherPersonService {

private DBOpenHelp openHelp=null;
private Context context;


public OtherPersonService(Context context) {
this.context = context;
        openHelp=new DBOpenHelp(context);
    }

public void save(Person person){
        SQLiteDatabase database= openHelp.getWritableDatabase();//對資料要更改,該方法以讀和寫的方式開啟資料庫,有緩衝功能
//database.execSQL("insert into person(name) values(?)",new Object[]{person.getName()});
        ContentValues values=new ContentValues();
        values.put("name", person.getName());
        database.insert("person", null, values);//不管有沒有資料都想資料庫裡面儲存資料,
//database.insert("person", "name", null);//如果沒有給定第三個欄位或第三個參數個數為0個，那個就要指定一個空值欄位
    }

public void update(Person person){
        SQLiteDatabase database= openHelp.getWritableDatabase();
//database.execSQL("update person set name=? where personid=?",new Object[]{person.getName(),person.getPersonId()});
        ContentValues values=new ContentValues();
        values.put("name", person.getName());
        database.update("person", values, "personid=?", new String[]{String.valueOf(person.getPersonId())});
    }

public void delete(int personId){
        SQLiteDatabase database= openHelp.getWritableDatabase();
//database.execSQL("delete from person where personid=?",new Object[]{personId});
        database.delete("person", "personid=?", new String[]{String.valueOf(personId)});
    }

public Person find(int personId){
        SQLiteDatabase database= openHelp.getWritableDatabase();
        Person person=null;
//Cursor cursor= database.rawQuery("select * from person where personid=?", new String[]{String.valueOf(personId).toString()});
        Cursor cursor=database.query("person", new String[]{"personid","name"}, 
"personid=?", new String[]{String.valueOf(personId)}, null, null, null);
if(cursor.moveToFirst()){//如果移動成功了表示存在
            int personIda =cursor.getInt(cursor.getColumnIndex("personid"));
            String name=cursor.getString(cursor.getColumnIndex("name"));
            person=new Person(personIda,name);
        }
        cursor.close();
return person;
    }

public List<Person> getScrollDate(int offerset,int maxResult){
        List<Person> persons=new ArrayList<Person>();
        SQLiteDatabase database= openHelp.getWritableDatabase();
//String sql="select * from person limit ?,?";
//Cursor cursor= database.rawQuery(sql, new String[]{String.valueOf(offerset),String.valueOf(maxResult)});
    
        Cursor cursor=database.query("person", null, null, null, null, null, null, offerset+","+maxResult);
while(cursor.moveToNext()){
int personIda =cursor.getInt(cursor.getColumnIndex("personid"));
            String name=cursor.getString(cursor.getColumnIndex("name"));
            Person person=new Person(personIda,name);
            persons.add(person);
        }
return persons;
    }

public long getCount(){
        SQLiteDatabase database= openHelp.getWritableDatabase();
//Cursor cursor= database.rawQuery("select count(*) from person", null);
        Cursor cursor=database.query("person", new String[]{"count(*)"}, null, null, null, null, null);
        cursor.moveToFirst();
int count=cursor.getInt(0);
        cursor.close();
return count;
    }
}

當資料庫更新的時候只要把版本號碼更新就會執行onUpgrade