如何在Android的“共享首选项”中使用主键？

Question

I am novice to android. I want to use sharedpreferences in my app. I want to use id as primary key so that it is auto incremented whenever I add a new string value. It can be done by using SQLite, but that is very lengthy task. I want to make my app simple.

The insert.xml file is as follows:

package com.example.shiza.dailyquranquote;

import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;


public class InsertVerse extends ActionBarActivity {
    EditText verseContent;
    EditText verseId;


    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_insert_verse);
    }
    public void saveVerse( View view)
    {
        verseContent = (EditText)findViewById(R.id.insertVerse);
        verseId = (EditText)findViewById(R.id.insertId);


        SharedPreferences sharedPreferences = getSharedPreferences("QuranVerse",0);

        Editor editor = sharedPreferences.edit();

        editor.putInt("id", Integer.parseInt( verseId.getText().toString()));
        editor.putString("verse", verseContent.getText().toString());

    }

}

Answer 1

SharedPreferences is not a database. It's a file with pair key/value stored.

So for instance if you put a pair "id"/5, after you put a pair "id"/6, when the pair "id"/5 will be replaced by new pair "id"/6.

Please have a look at:

http://developer.android.com/reference/android/content/SharedPreferences.html

http://developer.android.com/guide/topics/data/data-storage.html#pref

EDIT 1

SharedPreferences is typically used to store settings, counters, parameters, info about owner of device,...

Database are used to store multiple same records, for instance, list of users, list of products, ...

Answer 2

Use SQLiteOpenHelper

http://www.androidhive.info/2011/11/android-sqlite-database-tutorial/

see this link

Answer 3

In SharedPreferences you can't set primary key because it's a Key/Value pair. but, you can surely have multiple value for one key like

id: 0;1;2

and

name: John Smith;Rickey Watson;Martin Guptill

Now,

0 is John Smith,
1 is Ricky watson and 
2 is Marting Guptill.

this is might be something you're looking for...

Answer 4

Applicable only if you want one record (key) and every time you add new String the id count will be incremented. But if you have multiple records follow @LaurentY and @user94685231

public void saveVerse( View view)
        {
            verseContent = (EditText)findViewById(R.id.insertVerse);
            verseId = (EditText)findViewById(R.id.insertId);


            SharedPreferences sharedPreferences = getSharedPreferences("QuranVerse",0);
            int count=sharedPreferences.getInt("id",0);
            count++;
            Editor editor = sharedPreferences.edit();

            editor.putInt("id", count);
            editor.putString("verse", verseContent.getText().toString());

        }