[置顶] android orm映射框架（类似hibernate）基本使用

android orm映射框架，可像hibernate一样操作数据库。以下代码是我从网上摘录下来的，仅供参考.

packagecom.cng.utils;
importjava.sql.SQLException;
importandroid.content.Context;
importandroid.database.sqlite.SQLiteDatabase;
importandroid.util.Log;
importcom.cng.modal.Hello;
importcom.j256.ormlite.android.apptools.OrmLiteSqliteOpenHelper;
importcom.j256.ormlite.dao.Dao;
importcom.j256.ormlite.support.ConnectionSource;
importcom.j256.ormlite.table.TableUtils;
publicclassDataHelperextendsOrmLiteSqliteOpenHelper
{
privatestaticfinalStringDATABASE_NAME="HelloOrmlite.db";
privatestaticfinalintDATABASE_VERSION=1;
privateDao<Hello,Integer>helloDao=null;
publicDataHelper(Contextcontext)
{
super(context,DATABASE_NAME,null,DATABASE_VERSION);
}
@Override
publicvoidonCreate(SQLiteDatabasedb,ConnectionSourceconnectionSource)
{
try
{
TableUtils.createTable(connectionSource,Hello.class);
}catch(SQLExceptione)
{
Log.e(DataHelper.class.getName(),"创建数据库失败",e);
e.printStackTrace();
}
}
@Override
publicvoidonUpgrade(SQLiteDatabasedb,ConnectionSourceconnectionSource,
intarg2,intarg3)
{
try
{
TableUtils.dropTable(connectionSource,Hello.class,true);
onCreate(db,connectionSource);
}catch(SQLExceptione)
{
Log.e(DataHelper.class.getName(),"更新数据库失败",e);
e.printStackTrace();
}
}
@Override
publicvoidclose()
{
super.close();
helloDao=null;
}
publicDao<Hello,Integer>getHelloDataDao()throwsSQLException
{
if(helloDao==null)
{
helloDao=getDao(Hello.class);
}
returnhelloDao;
}
}

packagecom.cng;
importjava.sql.SQLException;
importjava.util.List;
importcom.cng.modal.Hello;
importcom.cng.utils.DataHelper;
importcom.j256.ormlite.android.apptools.OrmLiteBaseActivity;
importcom.j256.ormlite.dao.Dao;
importandroid.os.Bundle;
importandroid.widget.TextView;
publicclassOrmliteLoginActivityextendsOrmLiteBaseActivity<DataHelper>
{
@Override
publicvoidonCreate(BundlesavedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
TextViewtv=(TextView)this.findViewById(R.id.output);
try
{
Dao<Hello,Integer>helloDao=getHelper().getHelloDataDao();
//添加数据
for(inti=0;i<2;i++)
{
Hellohello=newHello("Hello"+i);
helloDao.create(hello);
}
tv.setText(tv.getText()+"\n"+"添加数据完成");
//查询添加的数据
List<Hello>hellos=helloDao.queryForAll();
for(Helloh:hellos)
{
tv.setText(tv.getText()+"\n"+h.toString());
}
//删除数据第一条数据
helloDao.delete(hellos.get(0));
tv.setText(tv.getText()+"\n"+"删除数据完成");
//重新查询数据
hellos=helloDao.queryForAll();
for(Helloh:hellos)
{
tv.setText(tv.getText()+"\n"+h.toString());
}
//修改数据
Helloh1=hellos.get(0);
h1.setWord("这是修改过的数据");
tv.setText(tv.getText()+"\n"+"修改数据完成");
helloDao.update(h1);
//重新查询数据
hellos=helloDao.queryForAll();
for(Helloh:hellos)
{
tv.setText(tv.getText()+"\n"+h.toString());
}
}catch(SQLExceptione)
{
//TODOAuto-generatedcatchblock
e.printStackTrace();
}
}
}

packagecom.cng.modal;
importandroid.R.integer;
importcom.j256.ormlite.field.DatabaseField;
publicclassHello
{
@DatabaseField(generatedId=true,unique=true)
intid;
@DatabaseField
Stringword;
//这是必须加的，否则会出错
publicHello(){}
publicintgetId()
{
returnid;
}
publicHello(Stringword)
{
super();
this.word=word;
}
publicvoidsetId(intid)
{
this.id=id;
}
publicStringgetWord()
{
returnword;
}
publicvoidsetWord(Stringword)
{
this.word=word;
}
@Override
publicStringtoString()
{
StringBuildersb=newStringBuilder();
sb.append("id=").append(id);
sb.append(",word=").append(word);
returnsb.toString();
}
}

就这三个类，datahelper是操作数据库的类，可新建，更新表，Hello是一个映射到数据库表的类，具体的看api 文档的下载地址是http://ormlite.com/releases/(其中的jar包也在这里下载) OrmliteLoginActivity就是activity类，它没继承activity，而是继承了OrmLiteBaseActivity类。

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