Android sqlite

转载 http://blog.csdn.net/s874154731/article/details/7086238

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;
import android.util.Log;
public class DatabaseHelper extends SQLiteOpenHelper {
    static String dbName= "mydb.db";
    static int dbVersion = 2;
    public DatabaseHelper(Context context) {
        super(context, dbName, null, dbVersion);
    }
    //只在初次使用数据库的时候会被自动调用一次
    public void onCreate(SQLiteDatabase db) {
        Log.i("TAG","onCrete被调用了");
        String sql = "create table person(personid integer primary key autoincrement," +
                "name varchar(20), age integer)";
        db.execSQL(sql);
    }
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        Log.i("TAG","onUpgrade被调用了");
        String sql = "alter table person add phone char(20) null";
        db.execSQL(sql);
    }
}  

import java.util.ArrayList;
import java.util.List;
import android.content.Context;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import cn.class3g.domain.Person;
public class PersonService {
    private DatabaseHelper dbHelper;
    public PersonService(Context context){
        dbHelper = new DatabaseHelper(context);
    }
    public void add(Person person){
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        String sql = "insert into person(name, age, phone) values(?,?,?)";
        db.execSQL(sql,new Object[]{person.getName(), person.getAge(), person.getPhone()});
    }
        public void delete(int id){
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        String sql = "delete from person where personid=?";
        db.execSQL(sql,new Object[]{id});
    }
    public void update(Person person, int id){
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        String sql = "update person set name=?, age=?, phone=? where personid=?";
        db.execSQL(sql,new Object[]{person.getName(),person.getAge(),person.getPhone(), id});
    }
    public Person find(int id){
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        String sql = "select * from person where personid=?";
        Cursor cursor = db.rawQuery(sql, new String[]{String.valueOf(id) });
        if(cursor.moveToNext()){
            Person person = new Person();
            person.setPersionid(cursor.getInt(0));
            person.setName(cursor.getString(cursor.getColumnIndex("name")));
            person.setAge(cursor.getInt(2));
            person.setPhone(cursor.getString(3));
            return person;
        }
        return null;
    }
    public int getRecordsCount(){
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        String sql = "select count(*) from person";
        Cursor cursor = db.rawQuery(sql, null);
        cursor.moveToFirst();
        int count = cursor.getInt(0);
        cursor.close();
        return count;
    }
    //跳过前面的start条记录，读取其后count记录
    public List<Person> getScrollData(int start, int count){
        SQLiteDatabase db = dbHelper.getReadableDatabase();
        String sql = "select * from person limit ?,?";
        Cursor cursor = db.rawQuery(sql,
                        new String[] { String.valueOf(start),
                                       String.valueOf(count) });
        List<Person> list = new ArrayList<Person>();
        while(cursor.moveToNext()){
            Person p = new Person();
            p.setPersionid(cursor.getInt(0));
            p.setName(cursor.getString(1));
            p.setAge(cursor.getInt(2));
            list.add(p);
        }
        cursor.close();
        return list;
    }
}