安卓学习：（6）安卓操作sqlite数据库

1.编写DataBaseOpenHelper公共类

package com.smart.service;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteDatabase.CursorFactory;
import android.database.sqlite.SQLiteOpenHelper;

public class DataBaseOpenHelper extends SQLiteOpenHelper {
  // 数据名称，
  private static final String DBNAME = "smrtDataBase";
  // 数据库版本
  private static final int version = 1;

  // 构造方法参数，
  public DataBaseOpenHelper(Context context) {
    super(context, DBNAME, null, version);
  }

  // 数据库创建表的名子。
  @Override
  public void onCreate(SQLiteDatabase db) {
    db.execSQL("CREATE TABLE person (personid integer primary key autoincrement,name varchar(20),age INTEGER)");

  }

  // 更新方法
  @Override
  public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
    db.execSQL("EROP TABLE IF EXISTS person");
    onCreate(db);
  }

}

2.编写Person实体类

package com.smart.domain;

public class Person {

  @Override
  public String toString() {

    return "personid=" + personid + ",name=" + name + ",age=" + age;
  }

  public int personid;
  public String name;
  public Short age;

  public int getPersonid() {
    return personid;
  }

  public void setPersonid(int personid) {
    this.personid = personid;
  }

  public String getName() {
    return name;
  }

  public void setName(String name) {
    this.name = name;
  }

  // 增加一个构造器
  public Person(int personid, String name, Short age) {
    super();
    this.personid = personid;
    this.name = name;
    this.age = age;
  }

  // 创建构造器
  public Person(String name, short age) {
    this.name = name;
    this.age = age;

  }

  public Short getAge() {
    return age;
  }

  public void setAge(Short age) {
    this.age = age;
  }

}

3.编写PersonService类

package com.smart.service;

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

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

import com.smart.domain.Person;

public class PersonService {
  /**
   * 这里是处理业务的方法，和JAVA叫做实现类 如果用上下文打开数据库，一定要关闭数据库
   * */
  private DataBaseOpenHelper dbOpenHelper;

  public PersonService(Context context) {

    dbOpenHelper = new DataBaseOpenHelper(context);
  }

  public void save(Person person) {
    SQLiteDatabase database = dbOpenHelper.getWritableDatabase();
    database.execSQL("insert into person(name,age) values(?,?)",
        new Object[] { person.getName(), person.getAge() });

    // database.close();
  }

  public void update(Person person) {
    SQLiteDatabase database = dbOpenHelper.getWritableDatabase();
    database.execSQL(
        "update person set name=?,age=? where personid=?",
        new Object[] { person.getName(), person.getAge(),
            person.getPersonid() });

  }

  public Person find(Integer id) {
    SQLiteDatabase database = dbOpenHelper.getWritableDatabase();
    Cursor cursor = database.rawQuery(
        "select * from person where personid=?",
        new String[] { String.valueOf(id) });
    if (cursor.moveToNext()) {
      return new Person(cursor.getInt(0), cursor.getString(1),
          cursor.getShort(2));

    }

    return null;
  }

  public void delete(Integer... ids) {

    if (ids.length > 0) {
      StringBuilder sb = new StringBuilder();
      for (Integer id : ids) {
        sb.append("?").append(",");
      }
      sb.deleteCharAt(sb.length() - 1);
      SQLiteDatabase database = dbOpenHelper.getWritableDatabase();
      database.execSQL(
          "delete from person where personid in(" + sb + ")",
          (Object[]) ids);

    }

  }

  // 分页代码
  public List<Person> getScrollData(int startResult, int maxResult) {
    List<Person> persons = new ArrayList<Person>();
    SQLiteDatabase database = dbOpenHelper.getWritableDatabase();
    Cursor cursor = database.rawQuery(
        "select * from person limit ?,?",
        new String[] { String.valueOf(startResult),
            String.valueOf(maxResult) });
    while (cursor.moveToNext()) {
      persons.add(new Person(cursor.getInt(0), cursor.getString(1),
          cursor.getShort(2)));
    }

    return persons;

  }

  // 取得所有的条数
  public long getCount() {
    SQLiteDatabase database = dbOpenHelper.getWritableDatabase();
    Cursor cursor = database.rawQuery("select * from person ", null);
    if (cursor.moveToNext()) {
      return cursor.getLong(0);
    }
    return 0;
  }

}

4.编写PersonServiceTest测试类

package com.smart.dh;

import java.util.Iterator;
import java.util.List;

import android.test.AndroidTestCase;
import android.util.Log;

import com.smart.domain.Person;
import com.smart.service.PersonService;

public class PersonServiceTest extends AndroidTestCase {

  private static final String TAG = "PersonServiceTest";

  // 保存数据。
  public void testSave() throws Exception {
    PersonService personService = new PersonService(this.getContext());
    // personService.save(new Person("老梁",(short)23));
    for (int i = 0; i < 10; i++) {
      personService.save(new Person("llb" + i, (short) (i + 1)));
    }

  }

  // 查询
  public void testFind() throws Exception {
    PersonService personService = new PersonService(this.getContext());
    Person person = personService.find(1);
    Log.i(TAG, person.toString());

    // personService.save(new Person("老梁",(short)23));
  }

  // 更新语句

  public void testUpdate() throws Exception {
    PersonService personService = new PersonService(this.getContext());
    Person person = personService.find(1);
    person.setName("smart");
    personService.update(person);

    Log.i(TAG, person.toString());

  }

  // 获得所有的条数
  public void testGetCount() throws Exception {
    PersonService personService = new PersonService(this.getContext());
    Log.i(TAG, String.valueOf(personService.getCount()));

  }

  // 分页功能
  public void testGetScrollData() throws Exception {
    PersonService personService = new PersonService(this.getContext());
    List persons = personService.getScrollData(0, 20);// 从0条到20条的数据
    for (Person person : persons) {
      Log.i(TAG, person.toString());
    }

  }

  public void testDelete() throws Exception {
    PersonService personService = new PersonService(this.getContext());
    personService.delete(1, 2, 3);// 删除1.2.3三条记录
  }

}

5.执行结果