Android অ্যাপ্লিকেশনে SQLite ডেটাবেস ব্যবহারের পূর্ণাঙ্গ গাইড

Android অ্যাপ্লিকেশনে SQLite ডেটাবেস ব্যবহারের পূর্ণাঙ্গ গাইড

এই টিউটোরিয়ালটি দেখায় কিভাবে একটি Android অ্যাপ্লিকেশনে SQLite ডেটাবেস ব্যবহার করে ডেটা সংরক্ষণ, পঠন, আপডেট এবং ডিলিট (CRUD অপারেশন) করা যায়। আমরা একটি ফুটবল খেলোয়াড়ের ডেটাবেস তৈরি করব যেখানে খেলোয়াড়ের নাম এবং দেশ সংরক্ষণ করা হবে।

প্রয়োজনীয় ধাপসমূহ

ধাপ ১: নতুন প্রজেক্ট তৈরি করুন

Android Studio-তে File → New Project এ যান এবং প্রজেক্ট তৈরি করুন।

ধাপ ২: মেইন লেআউট তৈরি করুন (res/layout/activity_main.xml)

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="https://schemas.android.com/apk/res/android"
    xmlns:tools="https://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="8dp"
    tools:context=".MainActivity">

    <ListView
        android:id="@+id/listView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:dividerHeight="1dp"
        android:padding="10dp" />

    <TextView
        android:id="@+id/textView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="কোনো ডেটা নেই" />

</RelativeLayout>

ধাপ ৩: DatabaseManager ক্লাস তৈরি করুন

এই ক্লাসটি ডেটাবেস অপারেশন (CRUD) হ্যান্ডেল করবে।

import android.content.ContentValues;
import android.content.Context;
import android.database.Cursor;
import android.database.SQLException;
import android.database.sqlite.SQLiteDatabase;

public class DataBaseManager {
    private DatabaseHelper databaseHelper;
    private Context context;
    private SQLiteDatabase database;

    DataBaseManager(Context c) {
        context = c;
    }

    DataBaseManager open() throws SQLException {
        databaseHelper = new DatabaseHelper(context);
        database = databaseHelper.getWritableDatabase();
        return this;
    }

    public void close() {
        databaseHelper.close();
    }

    void insert(String name, String desc) {
        ContentValues contentValue = new ContentValues();
        contentValue.put(DatabaseHelper.SUBJECT, name);
        contentValue.put(DatabaseHelper.DESCRIPTION, desc);
        database.insert(DatabaseHelper.TABLE_NAME, null, contentValue);
    }

    Cursor fetch() {
        String[] columns = new String[] {
            DatabaseHelper._ID,
            DatabaseHelper.SUBJECT,
            DatabaseHelper.DESCRIPTION
        };
        Cursor cursor = database.query(DatabaseHelper.TABLE_NAME, columns, null, null, null, null, null);
        if (cursor != null) {
            cursor.moveToFirst();
        }
        return cursor;
    }

    public int update(long _id, String name, String desc) {
        ContentValues contentValues = new ContentValues();
        contentValues.put(DatabaseHelper.SUBJECT, name);
        contentValues.put(DatabaseHelper.DESCRIPTION, desc);
        return database.update(DatabaseHelper.TABLE_NAME, contentValues, DatabaseHelper._ID + " = " + _id, null);
    }

    public void delete(long _id) {
        database.delete(DatabaseHelper.TABLE_NAME, DatabaseHelper._ID + "=" + _id, null);
    }
}

ধাপ ৪: DatabaseHelper ক্লাস তৈরি করুন

এই ক্লাসটি SQLiteOpenHelper kếর করে এবং ডেটাবেস তৈরির লজিক ধারণ করে।

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

class DatabaseHelper extends SQLiteOpenHelper {
    static final String TABLE_NAME = "FOOTBALLPLAYERS";
    static final String _ID = "_id";
    static final String SUBJECT = "subject";
    static final String DESCRIPTION = "description";

    private static final String DB_NAME = "PLAYER_COUNTRIES.DB";
    private static final int DB_VERSION = 1;

    private static final String CREATE_TABLE = "create table " + TABLE_NAME + "("
            + _ID + " INTEGER PRIMARY KEY AUTOINCREMENT, "
            + SUBJECT + " TEXT NOT NULL, "
            + DESCRIPTION + " TEXT);";

    DatabaseHelper(Context context) {
        super(context, DB_NAME, null, DB_VERSION);
    }

    @Override
    public void onCreate(SQLiteDatabase db) {
        db.execSQL(CREATE_TABLE);
    }

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
        onCreate(db);
    }
}

ধাপ ৫: MainActivity.java বাস্তবায়ন করুন

import android.content.Intent;
import android.database.Cursor;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SimpleCursorAdapter;
import android.widget.TextView;
import androidx.appcompat.app.AppCompatActivity;

public class MainActivity extends AppCompatActivity {
    DataBaseManager dataBaseManager;
    ListView listView;
    SimpleCursorAdapter adapter;

    final String[] from = new String[]{
        DatabaseHelper._ID,
        DatabaseHelper.SUBJECT,
        DatabaseHelper.DESCRIPTION
    };
    final int[] to = new int[]{R.id.id, R.id.title, R.id.desc};

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

        dataBaseManager = new DataBaseManager(this);
        dataBaseManager.open();

        Cursor cursor = dataBaseManager.fetch();
        listView = findViewById(R.id.listView);
        listView.setEmptyView(findViewById(R.id.textView));

        adapter = new SimpleCursorAdapter(this, R.layout.activity_view_record, cursor, from, to, 0);
        adapter.notifyDataSetChanged();
        listView.setAdapter(adapter);

        listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
            @Override
            public void onItemClick(AdapterView<?> parent, View view, int position, long viewId) {
                TextView idTextView = view.findViewById(R.id.id);
                TextView titleTextView = view.findViewById(R.id.title);
                TextView descTextView = view.findViewById(R.id.desc);

                String id = idTextView.getText().toString();
                String title = titleTextView.getText().toString();
                String desc = descTextView.getText().toString();

                Intent modifyIntent = new Intent(getApplicationContext(), ModifyPlayerActivity.class);
                modifyIntent.putExtra("title", title);
                modifyIntent.putExtra("desc", desc);
                modifyIntent.putExtra("id", id);
                startActivity(modifyIntent);
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        int id = item.getItemId();
        if (id == R.id.addRecord) {
            Intent addPlayer = new Intent(this, AddPlayerActivity.class);
            startActivity(addPlayer);
        }
        return super.onOptionsItemSelected(item);
    }
}

ধাপ ৬: AddPlayerActivity এবং ModifyPlayerActivity তৈরি করুন

AddPlayerActivity.java

import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import androidx.appcompat.app.AppCompatActivity;

public class AddPlayerActivity extends AppCompatActivity implements View.OnClickListener {
    Button btnAdd;
    private EditText editSubject;
    private EditText editDescription;
    private DataBaseManager dataBaseManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setTitle("রেকর্ড যোগ করুন");
        setContentView(R.layout.activity_addplayer);

        editSubject = findViewById(R.id.editTextSubject);
        editDescription = findViewById(R.id.editTextDescription);
        btnAdd = findViewById(R.id.add_record);
        dataBaseManager = new DataBaseManager(this);
        dataBaseManager.open();
        btnAdd.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        if (v.getId() == R.id.add_record) {
            final String name = editSubject.getText().toString();
            final String desc = editDescription.getText().toString();
            dataBaseManager.insert(name, desc);
            Intent main = new Intent(AddPlayerActivity.this, MainActivity.class)
                    .setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
            startActivity(main);
        }
    }
}

activity_addplayer.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="https://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="4dp">

    <EditText
        android:id="@+id/editTextSubject"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ems="10"
        android:hint="নাম লিখুন">
        <requestFocus />
    </EditText>

    <EditText
        android:id="@+id/editTextDescription"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="দেশ লিখুন"
        android:inputType="textMultiLine" />

    <Button
        android:id="@+id/add_record"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:text="রেকর্ড যোগ করুন" />

</LinearLayout>

ModifyPlayerActivity.java

import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

public class ModifyPlayerActivity extends AppCompatActivity implements View.OnClickListener {
    EditText editTextSub;
    Button updateBtn, deleteBtn;
    EditText editTextDesc;
    private long _id;
    DataBaseManager dataBaseManager;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setTitle("রেকর্ড সংশোধন করুন");
        setContentView(R.layout.activity_modify_player);

        dataBaseManager = new DataBaseManager(this);
        dataBaseManager.open();

        editTextSub = findViewById(R.id.editTextSub);
        editTextDesc = findViewById(R.id.editTextDesc);
        updateBtn = findViewById(R.id.btnUpdate);
        deleteBtn = findViewById(R.id.btnDelete);

        Intent intent = getIntent();
        String id = intent.getStringExtra("id");
        String name = intent.getStringExtra("title");
        String desc = intent.getStringExtra("desc");

        _id = Long.parseLong(id);
        editTextSub.setText(name);
        editTextDesc.setText(desc);

        updateBtn.setOnClickListener(this);
        deleteBtn.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()) {
            case R.id.btnUpdate:
                String title = editTextSub.getText().toString();
                String desc = editTextDesc.getText().toString();
                dataBaseManager.update(_id, title, desc);
                this.returnHome();
                break;
            case R.id.btnDelete:
                dataBaseManager.delete(_id);
                this.returnHome();
                break;
        }
    }

    public void returnHome() {
        Intent home_intent = new Intent(getApplicationContext(), MainActivity.class)
                .setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
        startActivity(home_intent);
    }
}

activity_modify_player.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="https://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="10dp">

    <EditText
        android:id="@+id/editTextSub"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginBottom="10dp"
        android:ems="10"
        android:hint="নাম লিখুন" />

    <EditText
        android:id="@+id/editTextDesc"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:hint="দেশ লিখুন" />

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:weightSum="2"
        android:gravity="center_horizontal"
        android:orientation="horizontal">

        <Button
            android:id="@+id/btnUpdate"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="আপডেট" />

        <Button
            android:id="@+id/btnDelete"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_weight="1"
            android:text="ডিলিট" />

    </LinearLayout>
</LinearLayout>

ধাপ ৭: লিস্ট সারি লেআউট তৈরি করুন (list_row.xml)

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="https://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:padding="4dp">

    <TextView
        android:id="@+id/id"
        android:layout_width="25dp"
        android:layout_height="wrap_content"
        android:layout_alignParentStart="true"
        android:layout_alignParentTop="true"
        android:layout_marginEnd="6dp"
        android:padding="3dp"
        android:visibility="visible" />

    <TextView
        android:id="@+id/title"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="10dp"
        android:layout_toEndOf="@id/id"
        android:maxLines="1"
        android:padding="3dp"
        android:textSize="17sp"
        android:textStyle="bold" />

    <TextView
        android:id="@+id/desc"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_below="@id/title"
        android:layout_marginStart="10dp"
        android:layout_toEndOf="@id/id"
        android:ellipsize="end"
        android:maxLines="2"
        android:padding="3dp"
        android:visibility="visible" />

</RelativeLayout>

ধাপ ৮: AndroidManifest.xml আপডেট করুন

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="https://schemas.android.com/apk/res/android"
    package="app.com.sample">

    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">

        <activity android:name=".ModifyPlayerActivity"></activity>
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity android:name=".AddPlayerActivity" />

    </application>
</manifest>

মেনু রিসোর্স (res/menu/main.xml)

অপশন মেনুতে "রেকর্ড যোগ করুন" বাটন যোগ করার জন্য:

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="https://schemas.android.com/apk/res/android"
    xmlns:app="https://schemas.android.com/apk/res-auto">
    <item
        android:id="@+id/addRecord"
        android:title="রেকর্ড যোগ করুন"
        app:showAsAction="never" />
</menu>

অ্যাপ্লিকেশন চালানোর পদ্ধতি

আপনার Android ডিভাইস কম্পিউটারের সাথে সংযুক্ত করুন। Android Studio-তে Run আইকনে ক্লিক করুন এবং ডিভাইসে আউটপুট দেখুন।