عملیات CRUD در اندروید با استفاده از دیتابیس SQLite و SqliteOpenHelper

 public class items {
int id;
String desc;
String alarm;
String time;

public items(int id, String desc , String alarm , String time){
    this.id = id;
    this.desc = desc;
    this.alarm = alarm;
    this.time = time;
}
}

 class Item() {
     var id: Int = 0;
     var desc: String = "";
     var time: String = "";
     var alaram: String = "";
constructor( id: Int,  desc: String,  time: String,  alarm: String) : this() {
    this.id = id
    this.desc = desc
    this.time = time
    this.alaram = alaram
}
}

 public class ItemsDatabaseHelper extends SQLiteOpenHelper {
  public itemsdbh(@Nullable Context context) {
   // Database Info
     private static final String DATABASE_NAME = "postsDatabase";
     private static final int DATABASE_VERSION = 1;
         super(context, DATABASE_NAME, null, DATABASE_VERSION);
     }

public class ItemsDatabaseHelper(val context: Context, val dbName:String, val version: Int)
     : SQLiteOpenHelper(context,dbName,null,version) {

    @Override
     public void onCreate(SQLiteDatabase sqLiteDatabase) {
         String CREATE_USERS_TABLE = "CREATE TABLE " + TABLE_ITEMS +
                 "(" +
                 KEY_ITEM_ID + " INTEGER PRIMARY KEY," +
                 KEY_ITEM_DESC + " TEXT," +
                 KEY_ITEM_TIME + " TEXT," +
                 KEY_ITEM_ALARM + " TEXT," +
                 ")";
   sqLiteDatabase.execSQL(CREATE_USERS_TABLE);
}

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

 override fun onUpgrade(db: SQLiteDatabase, oldVersion: Int, newVersion: Int) {
         if (oldVersion != newVersion) {
             db.execSQL("DROP TABLE IF EXISTS " + TABLE_ITEMS);
             onCreate(db);
         }
     }
override fun onCreate(db: SQLiteDatabase) {

    val CREATE_USERS_TABLE = "CREATE TABLE " + TABLE_ITEMS +
            "(" +
            KEY_ITEM_ID + " INTEGER PRIMARY KEY," +
            KEY_ITEM_DESC + " TEXT," +
            KEY_ITEM_ALARM + " TEXT," +
            KEY_ITEM_TIME + " TEXT" +
            ")"

    db.execSQL(CREATE_USERS_TABLE)
}

  public void addItem(Item item) {
         SQLiteDatabase db = getWritableDatabase(); 
   db.beginTransaction();
    try {

        ContentValues values = new ContentValues();
        values.put(KEY_ITEM_ID , item.id);
        values.put(KEY_ITEM_DESC , item.desc);
        values.put(KEY_ITEM_TIME , item.time);
        values.put(KEY_ITEM_ALARM, item.alarm);

        db.insertOrThrow(TABLE_ITEMS, null, values);
        db.setTransactionSuccessful();
    } catch (Exception e) {
        Log.d(TAG, "Error while trying to add post to database");
    } finally {
        db.endTransaction();
    }
}

public fun addItem(item: Item){
    val db = writableDatabase

    db.beginTransaction()

    val values= ContentValues()
    values.put(KEY_ITEM_ID , item.id)
    values.put(KEY_ITEM_DESC , item.desc)
    values.put(KEY_ITEM_TIME , item.time)
    values.put(KEY_ITEM_ALARM, item.alaram)

    db.insertOrThrow(TABLE_ITEMS,null,values)
    db.setTransactionSuccessful()
}

 public List getAllItems() {
         List list = new ArrayList<>();   

    String itemQuery = String.format(
            "SELECT * FROM %s ",
            TABLE_ITEMS
    );

    SQLiteDatabase db = getReadableDatabase();
    Cursor cursor = db.rawQuery(itemQuery, null);
    try {
        if (cursor.moveToFirst()) {
            do {
                Item newPost = new Item();
                newPost.id= cursor.getInt(cursor.getColumnIndex(KEY_ITEM_ID));
                newPost.desc= cursor.getString(cursor.getColumnIndex(KEY_ITEM_DESC));
                newPost.time= cursor.getString(cursor.getColumnIndex(KEY_ITEM_TIME));
                newPost.alarm= cursor.getString(cursor.getColumnIndex(KEY_ITEM_ALARM));
                list.add(newPost);
            } while(cursor.moveToNext());
        }
    } catch (Exception e) {
        Log.d(TAG, "Error while trying to get posts from database");
    } finally {
        if (cursor != null && !cursor.isClosed()) {
            cursor.close();
        }
    }
    return list;
}

   public fun getAllItems(): List{
         val list = ArrayList()    
val itemQuery = String.format(
        "SELECT * FROM %s ",
        TABLE_ITEMS
    )

    val db = readableDatabase
    val cursor = db.rawQuery(itemQuery, null)
    try {
        if (cursor!!.moveToFirst()) {
            do {
                val newPost = Item()
                newPost.id= cursor.getInt(cursor.getColumnIndex(KEY_ITEM_ID))
                newPost.desc= cursor.getString(cursor.getColumnIndex(KEY_ITEM_DESC))
                newPost.time= cursor.getString(cursor.getColumnIndex(KEY_ITEM_TIME))
                newPost.alaram= cursor.getString(cursor.getColumnIndex(KEY_ITEM_ALARM))
                list.add(newPost)
            } while (cursor.moveToNext())
        }
    } catch (e: Exception) {
        Log.d(TAG, "Error while trying to get posts from database")
    } finally {
        if (cursor != null && !cursor.isClosed) {
            cursor.close()
        }
    }
    return list
}

 public int updateUserProfilePicture(Item item) {
         SQLiteDatabase db = this.getWritableDatabase();
    ContentValues values = new ContentValues();
    values.put(KEY_ITEM_ID , item.id);
    values.put(KEY_ITEM_DESC , item.desc);
    values.put(KEY_ITEM_TIME , item.time);
    values.put(KEY_ITEM_ALARM, item.alarm);

    return db.update(TABLE_ITEMS, values, KEY_ITEM_ID + " = ?",
            new String[] { String.valueOf(item.id) });
}

  public fun updateItem(item : Item): Int{
         val db = this.writableDatabase   
 val values = ContentValues()
    values.put(KEY_ITEM_DESC, item.desc)
    values.put(KEY_ITEM_TIME, item.time)
    values.put(KEY_ITEM_ALARM, item.alaram)

    return db.update(
        TABLE_ITEMS, values, KEY_ITEM_ID + " = ?", arrayOf(item.id.toString())
    )
}

      public int deleteItem(Item item){
         SQLiteDatabase db = getWritableDatabase();
    return db.delete(
            TABLE_ITEMS,  KEY_ITEM_ID + " = ?", new String[]{String.valueOf(item.id)});
}

    public fun deleteItem(item: Item): Int{
         val db = this.writableDatabase 
    return db.delete(
        TABLE_ITEMS,  KEY_ITEM_ID + " = ?", arrayOf(item.id.toString())
    )
}

 public void deleteAllItems() {
         SQLiteDatabase db = getWritableDatabase();
         db.beginTransaction();
         try {
             db.delete(TABLE_ITEMS, null, null);
             db.setTransactionSuccessful();
         } catch (Exception e) {
             Log.d(TAG, "Error while trying to delete all posts and users");
         } finally {
             db.endTransaction();
         }
     }

   fun deleteAllItems() {
         val db = writableDatabase
         db.beginTransaction()
         try {
             db.delete(TABLE_ITEMS, null, null)
             db.setTransactionSuccessful()
         } catch (e: Exception) {
             Log.d(TAG, "Error while trying to delete all posts and users")
         } finally {
             db.endTransaction()
         }
     }