How to Connect SQLite Database in Android & A Simple App: "Accessing Data With Android Cursors"

Hi Everyone! I'd showed you how to do an application on Android in the last article. This one is going to be about connection SQLite database and access data with cursors.

If you want to use your data or something else, should connect a database. Using SQLite on Android is so simple. There are so much SQLite Editor but I will use Firefox SQLite Manager in this article. For that, first open your Firefox Browser, then download SQLite Manager and as result go this directory: Tools/SQLite Manager. After that, you can range database. 

And now, it's time to ready our files we use to. Just follow this directories:


Documents:
1- src/DatabaseActivity.java
2- src/Database.java
3- layout/data.xml

We need "database.java" file, that's why is gotta a table on database. If you want to add something, I must have a database. Now, code Database.java file.

package database.connection;

import android.content.Context;
import android.database.sqlite.SQLiteDatabase;
import android.database.sqlite.SQLiteOpenHelper;


public class Database extends SQLiteOpenHelper {
 private static final String MYDATABASE = "names";
 private static final int VERSION = 1;

 public Database(Context connection) {
  super(connection, MYDATABASE, null, VERSION);
 }

 @Override
 public void onCreate(SQLiteDatabase db) {
  db.execSQL("CREATE TABLE mynames(id INTEGER PRIMARY KEY AUTOINCREMENT, name TEXT);");
 }

 @Override
 public void onUpgrade(SQLiteDatabase db, int arg1, int arg2) {
  db.execSQL("DROP TABLE IF EXIST mynames");
  onCreate(db);
 }
}

So, we've just created a database, as called MYDATABASE. Table's name is "names". There are two fields on it: "id and name". As you know that is all about SQL. If you know SQL, you can get it easily. id field is an integer piece of table. The other one is a text field.

We'got a database and a table of this. The form we can add data is what we need exactly. For that, gotta compose a Android XML File. This file will have a textfield widget and a button widget, that's it! Let's do data.xml file!

If you want, just look what we got up right now. We created a database, a table of this database and form widgets. I can add a data after make this platform up:) Let's do our platform: DatabaseActivity.java file

package database.connection;
//Those are included by the system 
import android.app.Activity;
import android.content.ContentValues;
import android.database.Cursor;
import android.database.sqlite.SQLiteDatabase;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
 
public class DataBaseActivity extends Activity {
    private DB names;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        // TODO Auto-generated method stub
        super.onCreate(savedInstanceState);
        setContentView(R.layout.data); //including layout/data.xml file
        names = new DB(this);
        final EditText name=(EditText) findViewById(R.id.editText1);
 
        Button senddata=(Button) findViewById(R.id.senddata);
 
        senddata.setOnClickListener(new View.OnClickListener() {
 
            public void onClick(View v) {
                    try{
                     AddDATA(name.getText().toString());
                     Cursor cursor = ShowDATA();
                     ShowDATA(cursor);
                     }
                     finally{
                     names.close();
                    }
            }
        });
 
    }
    
    private void AddDATA(String ResultName){

    SQLiteDatabase db = names.getWritableDatabase();
    ContentValues datas = new ContentValues();
    datas.put("name", ResultName);
    db.insertOrThrow("ournames", null, datas);
    }

    private String[] SELECT = {"id", "name"};

    private Cursor ShowDATA(){
    SQLiteDatabase db = names.getReadableDatabase();
    Cursor cursor = db.query("ournames", SELECT, null, null, null, null, null);

    startManagingCursor(cursor);
    return cursor;
    }

    private void ShowDATA(Cursor cursor){
        StringBuilder builder = new StringBuilder("RESULTS!:\n");

        while(cursor.moveToNext()){

        String whatthenameis = cursor.getString((cursor.getColumnIndex("name")));
        builder.append(whatthenameis).append("\n");
        }

        TextView text = (TextView)findViewById(R.id.textView1);
        text.setText(builder);
    }
}

Generally, coder need to use a database, while saving data. We use SQLite Database on Android'cuz it's simple. Here, SQL is as you know before. "SELECT" command using also. By the way, if you want to check your db file out, just go this directory on Eclipse: file explorer/data/[your project name]/database

Write Something

That's it! We can add and save our datas, through SQLite Database on Android.
When you write something and click button, data will been saved and can show it on the screen. We'll you guys next article!