SQLite数据库增删改查操作案例

Person实体类：

package com.ljq.domain;


public class Person {
    private Integer id;
    private String name;
    private String phone;

    public Person() {
        super();
    }

    public Person(String name,String phone) {
        super();
        this.name = name;
        this.phone = phone;
    }

    public Person(Integer id,String name,String phone) {
        super();
        this.id = id;
        this.name = name;
        this.phone = phone;
    }

    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 String getPhone() {
        return phone;
    }

    public void setPhone(String phone) {
        this.phone = phone;
    }

}

DBOpenHelper数据库关联类：

package com.ljq.db;

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

public class DBOpenHelper extends SQLiteOpenHelper {
    // 类没有实例化,是不能用作父类构造器的参数,必须声明为静态
    private static final String DBNAME = "ljq.db";
    private static final int VERSION = 1;

    // 第三个参数CursorFactory指定在执行查询时获得一个游标实例的工厂类,
    // 设置为null,代表使用系统默认的工厂类
    public DBOpenHelper(Context context) {
        super(context,DBNAME,null,VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL("CREATE TABLE PERSON (ID INTEGER PRIMARY KEY AUTOINCREMENT,NAME VARCHAR(20),PHONE VARCHAR(20))");
    }

    @Override
    public void onUpgrade(SQLiteDatabase db,int oldVersion,int newVersion) {
        // 注：生产环境上不能做删除操作
        db.execSQL("DROP TABLE IF EXISTS PERSON"); 
        onCreate(db);
    }
}

PersonService业务类：

package com.ljq.db;

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

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

import com.ljq.domain.Person;

public class PersonService {
    private DBOpenHelper dbOpenHelper = null;

    /** * 构造函数 * * 调用getWritableDatabase()或getReadableDatabase()方法后，会缓存SQLiteDatabase实例； * 因为这里是手机应用程序，一般只有一个用户访问数据库，所以建议不关闭数据库，保持连接状态。 * getWritableDatabase()，getReadableDatabase的区别是当数据库写满时，调用前者会报错，调用后者不会， * 所以如果不是更新数据库的话，最好调用后者来获得数据库连接。 * * 对于熟悉SQL语句的程序员最好使用exeSQL(),rawQuery(),因为比较直观明了 * * @param context */ 
    public PersonService(Context context){
        dbOpenHelper = new DBOpenHelper(context);
    }

    public void save(Person person){
        dbOpenHelper.getWritableDatabase().execSQL("insert into person(name,phone) values (?,?)",new Object[]{person.getName(),person.getPhone()});
    }

    public void update(Person person){
        dbOpenHelper.getWritableDatabase().execSQL("update person set name=?,phone=? where id=?",person.getPhone(),person.getId()});
    }

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

    public Person find(Integer id){
        Cursor cursor = dbOpenHelper.getReadableDatabase().rawQuery("select id,name,phone from person where id=?",new String[]{String.valueOf(id)});
        if(cursor.moveToNext()){
            int personid = cursor.getInt(0);
            String name = cursor.getString(1);
            String phone = cursor.getString(2);
            return new Person(personid,phone);
        }
        return null;
    }

    public long getCount(){
        Cursor cursor = dbOpenHelper.getReadableDatabase().query("person",new String[]{"count(*)"},null);
        if(cursor.moveToNext()){
            return cursor.getLong(0);
        }
        return 0;
    }

    /** * 分页 * * @param startResult 偏移量，默认从0开始 * @param maxResult 每页显示的条数 * @return */
    public List<Person> getScrollData(int startResult,int maxResult){
        List<Person> persons = new ArrayList<Person>();
        //Cursor cursor = dbOpenHelper.getReadableDatabase().query("person",new String[]{"id,phone"},
        // "name like ?",new String[]{"%ljq%"},null,"id desc","1,2");
        Cursor cursor = dbOpenHelper.getReadableDatabase().rawQuery("select * from person limit ?,?",new String[]{String.valueOf(startResult),String.valueOf(maxResult)});
        while(cursor.moveToNext()) {
            int personid = cursor.getInt(0); 
            String name = cursor.getString(1);
            String phone = cursor.getString(2);
            persons.add(new Person(personid,phone));
        }
        return persons;
    }



}

PersonServiceTest测试类

package com.ljq.test;

import java.util.List;

import com.ljq.db.PersonService;
import com.ljq.domain.Person;

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

public class PersonServiceTest extends AndroidTestCase{
    private final String TAG = "PersonServiceTest";

    public void testSave() throws Exception{
        PersonService personService = new PersonService(this.getContext());
        personService.save(new Person("zhangsan1","059188893343"));
        personService.save(new Person("zhangsan2","059188893343"));
        personService.save(new Person("zhangsan3","059188893343"));
        personService.save(new Person("zhangsan4","059188893343"));
        personService.save(new Person("zhangsan5","059188893343"));
    }

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

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

    public void testList() throws Exception{
        PersonService personService = new PersonService(this.getContext());
        List<Person> persons = personService.getScrollData(0,10);
        for(Person person : persons){
            Log.i(TAG,person.getId() + " : " + person.getName());
        }
    }

    public void testCount() throws Exception{
        PersonService personService = new PersonService(this.getContext());
        Log.i(TAG,String.valueOf(personService.getCount()));
    }

    public void testDelete() throws Exception{
        PersonService personService = new PersonService(this.getContext());
        personService.delete(1);
    }

    public void testDeleteMore() throws Exception{
        PersonService personService = new PersonService(this.getContext());
        personService.delete(new Integer[]{2,5,6});
    }
}

（编辑：李大同）

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