android sqlite crud operations class

android sqlite crud operations class

SQLite CRUD (Create, Read, Update, Delete) operation class in Android for a table with fields "id" (autoincrement), "name", "address", and "mobile_no".

First, create a new class called "DatabaseHelper" that extends the SQLiteOpenHelper class:

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

public class DatabaseHelper extends SQLiteOpenHelper {

    private static final String DATABASE_NAME = "mydatabase.db";
    private static final int DATABASE_VERSION = 1;

    // Table name
    private static final String TABLE_NAME = "mytable";

    // Column names
    private static final String COLUMN_ID = "id";
    private static final String COLUMN_NAME = "name";
    private static final String COLUMN_ADDRESS = "address";
    private static final String COLUMN_MOBILE_NO = "mobile_no";

    // SQL statement to create the table
    private static final String SQL_CREATE_TABLE =
            "CREATE TABLE " + TABLE_NAME + " (" +
                    COLUMN_ID + " INTEGER PRIMARY KEY AUTOINCREMENT," +
                    COLUMN_NAME + " TEXT," +
                    COLUMN_ADDRESS + " TEXT," +
                    COLUMN_MOBILE_NO + " TEXT)";

    public DatabaseHelper(Context context) {
        super(context, DATABASE_NAME, null, DATABASE_VERSION);
    }

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

    @Override
    public void onUpgrade(SQLiteDatabase db, int oldVersion, int newVersion) {
        // Drop table if exists and create new one
        db.execSQL("DROP TABLE IF EXISTS " + TABLE_NAME);
        onCreate(db);
    }

    // CRUD operations

    public void addData(String name, String address, String mobileNo) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(COLUMN_NAME, name);
        values.put(COLUMN_ADDRESS, address);
        values.put(COLUMN_MOBILE_NO, mobileNo);

        db.insert(TABLE_NAME, null, values);
        db.close();
    }

    public Cursor getAllData() {
        SQLiteDatabase db = this.getReadableDatabase();

        Cursor cursor = db.rawQuery("SELECT * FROM " + TABLE_NAME, null);

        return cursor;
    }

    public void updateData(int id, String name, String address, String mobileNo) {
        SQLiteDatabase db = this.getWritableDatabase();

        ContentValues values = new ContentValues();
        values.put(COLUMN_NAME, name);
        values.put(COLUMN_ADDRESS, address);
        values.put(COLUMN_MOBILE_NO, mobileNo);

        db.update(TABLE_NAME, values, COLUMN_ID + " = ?", new String[] { String.valueOf(id) });
        db.close();
    }

    public void deleteData(int id) {
        SQLiteDatabase db = this.getWritableDatabase();

        db.delete(TABLE_NAME, COLUMN_ID + " = ?", new String[] { String.valueOf(id) });
        db.close();
    }

}

        

In this code, the DATABASE_NAME and DATABASE_VERSION constants define the name and version number of the database. The TABLE_NAME constant defines the name of the table, and the COLUMN_ID, COLUMN_NAME, COLUMN_ADDRESS, and COLUMN_MOBILE_NO constants define the names of the columns in the table.
The SQL_CREATE_TABLE constant contains the SQL statement to create the table.
The addData() method inserts a new row into the table with the given name, address, and mobile number.
The getAllData() method returns a Cursor object containing all the rows in the table.
The updateData() method updates a row in the table with the given ID, name, address, and mobile number.