# greenDAO

**Repository Path**: HarmonyOS-tpc/greenDAO

## Basic Information

- **Project Name**: greenDAO
- **Description**: GreenDAO is a light & fast ORM that maps objects to SQLite databases.
- **Primary Language**: Unknown
- **License**: Apache-2.0
- **Default Branch**: master
- **Homepage**: None
- **GVP Project**: No

## Statistics

- **Stars**: 31
- **Forks**: 2
- **Created**: 2021-04-01
- **Last Updated**: 2025-09-02

## Categories & Tags

**Categories**: harmony, database-dev

**Tags**: None

## README

# GreenDao

GreenDAO is a light & fast ORM that maps objects to SQLite databases. Being highly optimized, greenDAO offers great performance and consumes minimal memory.
It relieves developers from dealing with low-level database requirements while saving development time

## Usage Instructions
1. A sample project which provides runnable code examples that demonstrate uses of the classes in this project is available in the sample/ folder.
   You can add new perrson info and delete person info by clicking on an existing person in the list.

2. The following core classes are the essential interface to greenDAO:
	**DaoMaster:** The entry point for using greenDAO. DaoMaster holds the database object (SQLiteDatabase) and manages DAO classes (not objects) for a specific schema. It has static methods to create the tables or drop them. Its inner classes OpenHelper and DevOpenHelper are SQLiteOpenHelper implementations that create the schema in the SQLite database.

	**DaoSession:** Manages all available DAO objects for a specific schema, which you can acquire using one of the getter methods. DaoSession provides also some generic persistence methods like insert, load, update, refresh and delete for entities. Lastly, a DaoSession objects also keeps track of an identity scope.

	**DAOs:** Data access objects (DAOs) persists and queries for entities. For each entity, greenDAO generates a DAO. It has more persistence methods than DaoSession, for example: count, loadAll, and insertInTx.

	Entities: Persistable objects. Usually, entities are objects representing a database row using standard Java properties (like a POJO or a JavaBean).


3. The steps to initialize the database and the core greenDAO classes:
	DaoMaster.DevOpenHelper helper = new DaoMaster.DevOpenHelper(this, "people-db");
	Database db = helper.getWritableDb();

	// get the person DAO
	DaoSession daoSession = new DaoMaster(db).newSession();
	personDao = daoSession.getPersonDao();


4. **QueryBuilder :** The QueryBuilder class lets you build custom queries for your entities without SQL and helps detect errors already at compile time.
	// query all people, sorted by their Name
    List<Person> people = personDao.queryBuilder().orderAsc(PersonDao.Properties.NAME).build().list();

## Features

* Setting up the database
* Creating the DAO session
* Inserting, Deleting and updating database 
* Queries, QueryBuilder, Order, Limit, Offset, and Pagination
* Query and LazyList, Executing Queries multiple times
* Raw queries, Delete queries
* Joins
* Database Encryption

## Installation Tutorial:
1. For using greendao in your sample application, add below dependencies:
    ```
    dependencies {
    	implementation project(path: ':greenDAOLib:greendaoapi')
    	implementation project(path: ':greenDAOLib:daocore')
    	implementation project(path: ':greenDAOLib:daogenerator')
    }
    ```

2. For using greendao in separate application, add the below dependencies and include greendao jars in libs folder of "entry" module:
    ```
    dependencies {
    	implementation files('libs/greendaoapi.har')
    	implementation files('libs/daocore.har')
    	implementation files('libs/daogenerator.har')
    }
    ```

	Also for above two cases add the sqlcipher dependency in daocore build.gradle :
    ```
    dependencies {
    	implementation 'io.openharmony.tpc.thirdlib:ohos-database-sqlcipher:1.0.2'
    }
    ```

3. For using greendao from a remote repository in separate application, add the below dependencies in build.gradle of "entry" module:
      ```
      dependencies {
          	implementation 'io.openharmony.tpc.thirdlib:greendaocore:1.0.0'
      }
      ```