GreenDao 使用教程 二

上一篇 总结了grendao 环境搭建以及简单的增删查改,接下来将全面解析框架的使用,基于上篇的orm模型（Note)数据库讲解GreenDao的插入:插入的方式有很多:1:daoSession.getNoteDao().insert(note);//插入note 如果note指定主键与表中已经存在了，就会发生异常（android.database.sqlite.SQLiteConstraintException: UNIQUE constraint failed: tb_note._id (code 1555)）而插入不进去

 daoSession.insert(note); 同上

2: daoSession.getNoteDao().insertOrReplace(note);

      当主键存在的时候会替换，所以能够很好的执行插入操作,推荐daoSession.insertOrReplace(note); 同上

3: 原生的sqlite

     String insertSql = String.format("insert into %s (%s,%s,%s) values('%s','%s','%s')",NoteDao.TABLENAME,NoteDao.Properties.Title.columnName,NoteDao.Properties.Content.columnName,NoteDao.Properties.CreateTime.columnName,note.getTitle(),note.getContent(),note.getCreateTime());   daoSession.getDatabase().execSQL(insertSql);

4:批量插入

   public void insertBatch(List<Note> notes){    daoSession.getNoteDao().insertInTx(notes);}

GreenDao的更新操作

1:单条更新(唯一性条件是主键相同)public void update(Note note) throws Exception {daoSession.update(note);//  daoSession.getNoteDao().update(note);}

2:批量更新

   //批量更新public void updateBatch(List<Note> notes) throws Exception {daoSession.getNoteDao().updateInTx(notes);}

3:原生sql：  

   public void updateSql(String sql){//  daoSession.getDatabase().execSQL("update .....");daoSession.getDatabase().execSQL(sql);}

GreenDao 的删除操作

1:单条删除(唯一性是主见相同)

   public void delete(Note note) throws Exception {      daoSession.delete(note);// daoSession.getNoteDao().delete(note);}

2: 单条删除 指定主键删除

   public void delete(long id) {daoSession.getNoteDao().deleteByKey(id);}

3:批量删除

  public void deleteBatch(List<Note> notes) {daoSession.getNoteDao().deleteInTx(notes);}

4:批量按主键删除

  // 批量按主键删除public void deleteBatchByKey(List<Long> pkIds) {daoSession.getNoteDao().deleteByKeyInTx(pkIds);}

5:删除所有

   public void deleteAll() throws Exception {daoSession.deleteAll(Note.class);//   daoSession.getNoteDao().deleteAll();}

6:原始sqlite语句

daoSession.getDatabase().execSQL(deletesql);

GreenDao 查询操作 也是最复杂的

1:单条查询

    //按主键查询public Note query(long pk) throws Exception {// daoSession.getNoteDao().load(pk);//按主见查询//daoSession.getNoteDao().load(rowId);//按行号查询return daoSession.load(Note.class, pk);}

2: QueryBuilder 复合查询[/code]

  
   public List<Note> queryBuider() throws Exception {//select from tb_note where Content like 'greendao'return daoSession.getNoteDao().queryBuilder().where(NoteDao.Properties.Content.like("greendao")).build().list();}

   public long queryBuider2(long pk) throws Exception {//select count(*) from tb_note where Content like 'greendao'return daoSession.getNoteDao().queryBuilder().where(NoteDao.Properties.Content.like("greendao")).buildCount().count();}

 public void queryBuider3() throws Exception {Cursor cursor = null;try {//CursorQuery 部分查询CursorQuery greendao = daoSession.getNoteDao().queryBuilder().where(NoteDao.Properties.Content.like("greendao")).buildCursor();cursor = greendao.query();while (cursor.moveToNext()) {long id = cursor.getInt(0);String title = cursor.getString(1);String content = cursor.getString(2);String time = cursor.getString(cursor.getColumnIndex(NoteDao.Properties.CreateTime.columnName));}} finally {if (cursor != null)cursor.close();}}

3:查询所有:

    public void queryAll(){daoSession.loadAll(Note.class);daoSession.queryBuilder(Note.class).build().list();daoSession.getNoteDao().queryBuilder().build().list();daoSession.getNoteDao().loadAll();}