GreenDao Introduction
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GreenDao is an ORM library that provides high performance for CRUD operations on SQLite databases in Android apps. It uses code generation to map objects to database tables, allowing data to be accessed and queried using objects rather than raw SQL. Some key features include object mapping, query building, caching, and bulk operations. The documentation provides examples of how to set up GreenDao in a project, define entity classes, perform queries, inserts, updates and deletes on objects.
![Sqlite review
• SQL Query
– Provider equal facebook
– Order by display order
– Limit data count100
• Cursor c = getContentResolver() . query
(uriLPageProvider , projection , selection,
selection args, sort order ) ;
(String ) selection :
StorageField.Provider. + "=?" =
(String[])selection args: {“facebook”}](https://image.slidesharecdn.com/greendaoheatonslider-151019032308-lva1-app6891/85/GreenDao-Introduction-11-320.jpg)
![Create main() in our case.
public class GreenDao {
public static void main(String[] args){
Schema schema = new Schema
(1, "com.acer.android.leftpage.provider");
Entity commonData = schema.addEntity("commonData");
commonData.setTableName("LeftPage");
commonData.addLongProperty("DataID").primaryKey();
commonData.addStringProperty("Category");
commonData.addStringProperty("Provider");
commonData.addLongProperty(“DisplayOrder”);
commonData.addContentProvider();
DaoGenerator generator = new DaoGenerator();
generator.generateAll
(schema, "../AcerHome/LeftPage/src/main/java/");}](https://image.slidesharecdn.com/greendaoheatonslider-151019032308-lva1-app6891/85/GreenDao-Introduction-19-320.jpg)
![Insert
• Insert:
– CommonDataDao .insert(new CommonData(DATA_ID,
arg1, arg2,x……));
• Bulk Insert
– CommonDataDao .insertln(CommonDataList);
– CommonDataDao.insertln(CommonData[]);
• InsetOrReplace
– CommonDataDao.insertOrReplaceln(CommonDataList)
Note: DATA_ID usually is null .](https://image.slidesharecdn.com/greendaoheatonslider-151019032308-lva1-app6891/85/GreenDao-Introduction-28-320.jpg)
![Update
• Update sentence
– CommonDataDao.update(new
CommonData(Data_ID , arg1 , arg2 , …….));
• Bulk Update
– CommonDataDao.updateln(CommonDataList);
– CommonDataDao.updateln(CommonData[]);
Note: DATA_ID must assign what
the row you want to update.](https://image.slidesharecdn.com/greendaoheatonslider-151019032308-lva1-app6891/85/GreenDao-Introduction-30-320.jpg)
GreenDao Introduction
- 2. Outline • Why GreenDao • Feature • Performance • How to getting start • How to use.
- 3. Why GreenDao • First . Some problem with DB Development. – No object orientation. – Data access sentence is low levely. – Always make same code to write SQL script. – Do you know SQL without 『||』. – I am stupid on SQL tuning • Second , it is faster than other ORM Lib.
- 5. Features • High Performance – CRD test. • ORM (Object relation mapping) – Code Generation – Read and write objects – CREATE TABLE done for you – Expressing Queries • Session cache • Setter ; getter • Create table “table_name” • Return List<Common>
- 6. Performance • Test case : – insert 10000 row – delete 10000 row – query 20000 row Test 1 Dao Content Provider Insert 1467 87268 (no transcation) Load 1608 9797 Delete 108 121 Test 2 Insert 662 87766 Load 1837 12282 delete 137 127
- 7. Benchmark • https://github.com/daj/android-orm- benchmark • Write 10000 • Read 10000
- 9. A example for presentation • Implement a social data collector • “Leftpage” as table name for database “leftpageProvider.db” • Every row data as “CommonData” • Column has – ”DataID” as primary key – “Category” – “Provider” – “DisplayOrder”
- 10. Expressing Queries: What difference • SQL Query all – Cursor c = mContext.getContentResolver().query(uriLPagePr ovider , projection , selection, selection args, sort order ) ; • GreenDao Load all List<commonData> datas = CommonDataDao.loadAll();
- 11. Sqlite review • SQL Query – Provider equal facebook – Order by display order – Limit data count100 • Cursor c = getContentResolver() . query (uriLPageProvider , projection , selection, selection args, sort order ) ; (String ) selection : StorageField.Provider. + "=?" = (String[])selection args: {“facebook”}
- 12. Sort order • SQL Query – Provider equal facebook – Order by display order – Limit data count100 • Cursor c = getContentResolver() . query (uriLPageProvider , projection , selection, selection args, sort order ) ; (String ) Sort order: StorageField.Displayorder
- 13. More detail • SQL Query – Provider equal facebook – Order by display order – Limit data count100 • Cursor c = getContentResolver() . query (uriLPageProvider , projection , selection, selection args, sort order ) ; (String ) Sort order: “ ASC ” + StorageField.Displayorder + “ LIMIT ” + request
- 14. If you are sqlite master • SQL Query – Provider equal facebook – Order by display order – Limit data count100 • Select * from leftpage where Provider = ‘facebook’ order asc ‘displayorder’ limit ‘100’ • Then you also load cusor and save to data list
- 15. But in GreenDao • SQL Query – Provider equal facebook – Order by display order – Limit data count100 mCommonDataDao.queryBuilder() .where(Properties.Provider.eq(Provider.Facebook)) .orderAsc(Properties.DisplayOrder) .limit(100) .list();
- 16. HOW TO GETTING START Create module
- 17. How to getting start? First time is terrible
- 18. Create a module to gen greendao code • In module gradle – Add Gradle script – compile 'de.greenrobot:greendao-generator:1.3.1
- 19. Create main() in our case. public class GreenDao { public static void main(String[] args){ Schema schema = new Schema (1, "com.acer.android.leftpage.provider"); Entity commonData = schema.addEntity("commonData"); commonData.setTableName("LeftPage"); commonData.addLongProperty("DataID").primaryKey(); commonData.addStringProperty("Category"); commonData.addStringProperty("Provider"); commonData.addLongProperty(“DisplayOrder”); commonData.addContentProvider(); DaoGenerator generator = new DaoGenerator(); generator.generateAll (schema, "../AcerHome/LeftPage/src/main/java/");}
- 20. Compile and run to Auto gen Core classes DaoMaster DaoSeesion CommonDataDao CommonData
- 21. In CommonDataDao public static void createTable(SQLiteDatabase db, boolean ifNotExists) { String constraint = ifNotExists? "IF NOT EXISTS ": ""; db.execSQL("CREATE TABLE " + constraint + "'LeftPage' (" + // "'DataID' INTEGER PRIMARY KEY AUTOINCREMENT ," + // 0: DataID "'Category' TEXT," + // 1: Category "'Provider' TEXT," + // 2: Provider "'DisplayOrder' INTEGER DEFAULT -1," + // 3: DisplayOrder "'Bookmarked' INTEGER DEFAULT 0," + // 4: Bookmarked "'Deleted' INTEGER DEFAULT 0," + // 5: Deleted "'Score' REAL DEFAULT -1," + // 6: Score "'Keywords' TEXT DEFAULT NULL," + // 7: Keywords
- 22. CommonData content public Long getDataID() { return DataID; } public void setDataID(Long DataID) { this.DataID = DataID; } …… …… ……
- 23. Add it and start to use • In Used Project gradle – compile 'de.greenrobot:greendao:1.3.7'
- 24. HOW TO USE INSERT , DELETE , UPDATE,
- 25. Initial • DaoMaster.DevOpenHelper helper = new DaoMaster.DevOpenHelper(context,”leftpage provider.db”); • DaoMaster master = new DaoMaster (helper.getDataBase()); • DaoSession session = master.newSession(); • CommonDataDao CommonDataDao= session.getCommonDataDao();
- 26. Query • Query with syntax – eq , notEq – ge , le , gt , lt – in , between – like • List<commonData> dataList = CommonDataDao.queryBuilder() .where(Properties.Provider.eq(Provider.Social)) .orderAsc(mCommonDataDao.Properties.DisplayOrder) .list();
- 27. Raw query SQLiteDatabase db = daoSession.getDatabase(); Cursor cursor = db.rawQuery("SELECT *FROM leftpage WHERE .....", null);
- 28. Insert • Insert: – CommonDataDao .insert(new CommonData(DATA_ID, arg1, arg2,x……)); • Bulk Insert – CommonDataDao .insertln(CommonDataList); – CommonDataDao.insertln(CommonData[]); • InsetOrReplace – CommonDataDao.insertOrReplaceln(CommonDataList) Note: DATA_ID usually is null .
- 29. Delete • Delete sentence – CommonDataDao.QueryBuilder() .where(Properties.Provider.eq(facebook)) .buildDelete() .executeDeleteWithoutDetachingEntities(); • Delete all – CommonDataDao.deleteAll();
- 30. Update • Update sentence – CommonDataDao.update(new CommonData(Data_ID , arg1 , arg2 , …….)); • Bulk Update – CommonDataDao.updateln(CommonDataList); – CommonDataDao.updateln(CommonData[]); Note: DATA_ID must assign what the row you want to update.
- 32. Something here AsyncSession asyncSession = DBHelper.getInstance(this).getAsyncSession(); asyncSession.insert( new CommonData(null, …, …));
Editor's Notes
- #4: 接下來投影片重點在於兩點 Feature Performance
- #6: High performance 比起其他 ormlite ，快了四倍 也比cp 快了不少
- #9: Content provider 也是一種 半成品 orm Sqlite 是一種 關聯式資料結構 OO 式一種開發概念 如何Mapping 簡單來說就是最後你希望你crud輸入和輸出的資料都是物件
- #11: 拿load all 來比 不太對吧
- #23: 作掉很多dirty job
- #24: 前置作業完成
- #26: Why use helper Master -> session -> commondataDao
- #27: Lazy list Id scope
- #29: 1. For not block MainThread 2. Data consistency