GreenDao Android Studio

Question

I\'m looking for a clear step-by-step explanation on how to import GreenDao in Android Studio.

I\'ve used it before in AS, but failed to get it to work again. There

Answer 1

Here's a step by step overview for Integrating GreenDao into your Android Project.

[ Reference How to use GeenDao with Android ? ]

[Project Link: GreenDao Example ]

PART1 : Setting Up GREENDAO

1. Create an android project.

2. Click File >New > New Module. Select Java Library and click Next.

3. Now we have to add the following Gradle Dependencies.

In build.gradle of Module:app, insert

compile 'de.greenrobot:greendao:2.1.0'

In the build.gradle of Module:greendao-generator, insert

compile 'de.greenrobot:greendao-generator:2.1.0'

Make sure, you sync your project.

4. Now in the MainGenerator.java,

we will define the database structure.

import de.greenrobot.daogenerator.DaoGenerator;
import de.greenrobot.daogenerator.Entity;
import de.greenrobot.daogenerator.Schema;

public class MainGenerator {
    public static void main(String[] args)  throws Exception {

        //place where db folder will be created inside the project folder
        Schema schema = new Schema(1,"com.codekrypt.greendao.db");

        //Entity i.e. Class to be stored in the database // ie table LOG
        Entity word_entity= schema.addEntity("LOG");

        word_entity.addIdProperty(); //It is the primary key for uniquely identifying a row

        word_entity.addStringProperty("text").notNull();  //Not null is SQL constrain

        //  ./app/src/main/java/   ----   com/codekrypt/greendao/db is the full path
        new DaoGenerator().generateAll(schema, "./app/src/main/java");

    }
}

5. Run MainGenerator.java

6. After running this, you will observe a newly created folder i.e. db in the Main Project Folder.

PART2 : Integrating it with Android Project

1. Set the activity_main.xml layout.

2. In MainActivity.java,

Add the following codes

package com.codekrypt.greendao;

import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;

import com.codekrypt.greendao.db.DaoMaster;
import com.codekrypt.greendao.db.DaoSession;
import com.codekrypt.greendao.db.LOG;
import com.codekrypt.greendao.db.LOGDao;

import java.util.List;

public class MainActivity extends AppCompatActivity {

    //Dao --> Data Access Object
    private LOGDao log_dao; // Sql access object
    private LOG temp_log_object; // Used for creating a LOG Object

    String log_text="";  //Entered text data is save in this variable

    private  final String DB_NAME ="logs-db" ;  //Name of Db file in the Device

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        //Initialise DAO
        log_dao=setupDb();

        //Setting up form elements
        Button textSave= (Button) findViewById(R.id.textSave);
        Button textTop= (Button) findViewById(R.id.textTop);
        final TextView textData=(TextView) findViewById(R.id.textData);

        assert textSave != null;
        textSave.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                log_text=textData.getText().toString();
                temp_log_object=new LOG(null,log_text);// Class Object, Id is auto increment

                SaveToSQL(temp_log_object);
            }
        });

        assert textTop != null;
        textTop.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                textData.setText( getFromSQL() );
            }
        });
    }

    //---------------------------------SQL QUERY Functions-----------------------------------------//
    public String getFromSQL(){
        List log_list = log_dao.queryBuilder().orderDesc(LOGDao.Properties.Id).build().list();  
        //Get the list of all LOGS in Database in descending order

        if(log_list.size()>0) {  //if list is not null

            return log_list.get(0).getText();
            //get(0)--> 1st object
            // getText() is the function in LOG class
        }
        return "";
    }

    public void SaveToSQL(LOG log_object) {
        log_dao.insert(log_object);
    }
    //----------------------------***END SQL QUERY***---------------------------------------------//


    //-------------------------------DB Setup Functions---------------------------------------------//

    //Return the Configured LogDao Object
    public LOGDao setupDb(){
        DaoMaster.DevOpenHelper masterHelper = new DaoMaster.DevOpenHelper(this, DB_NAME, null); //create database db file if not exist
        SQLiteDatabase db = masterHelper.getWritableDatabase();  //get the created database db file
        DaoMaster master = new DaoMaster(db);//create masterDao
        DaoSession masterSession=master.newSession(); //Creates Session session
        return masterSession.getLOGDao();
    }
    //-------------------------***END DB setup Functions***---------------------------------------//

}

3. Before Running the App, Make sure you have changed your configuration.

4. Now Run it.

PART 3 – VIEW THE SQL DB

1. Open Command Prompt.

2. Enter the following commands.

3. Opening the db file in SQLite3

4. Using SQLite3

PART 4 – EXTRAS

1. Structure (Core Classes) of GREENDAO