英文:
By adding same item to recyclerview in shopping cart its overriding
问题
如何在购物车系统中更新已存在的 RecyclerView 项？当我添加一个项目两次，然后如果我删除一个项目，那么第二个项目将会出现，仅在删除第一个项目后才会出现，使用 Java 在 Android Studio 中实现。
...
CartModel cart = new CartModel(namee, manufacture, avail_cart, e__pnum, m__pnum, String.valueOf(p), quantityy, String.valueOf(roundoff));
if (db.addToCart(cart)) {
// Toast.makeText(getApplicationContext(), "Product added to cart", Toast.LENGTH_LONG).show(); //roundoff
Snackbar.make(findViewById(android.R.id.content), "Product added to cart", Snackbar.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(), "Product not added to cart", Toast.LENGTH_LONG).show();
Snackbar.make(findViewById(android.R.id.content), "Product not added to cart", Snackbar.LENGTH_SHORT).show();
}
...
public boolean addToCart(CartModel cartModel) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(Manufacturer, cartModel.getManufacturer());
values.put(Availability, cartModel.getAvailability());
values.put(E_part, cartModel.getE_part());
values.put(M_part, cartModel.getM_part());
values.put(Unit_price, cartModel.getUnit_());
values.put(Quantity, cartModel.getQuantity());
values.put(Line_total, cartModel.getLine_total());
values.put(Name, cartModel.getName());
return db.insert(CartDetails, null, values) > 0;
}
请注意，这段代码是关于在购物车系统中添加商品并处理重复项的逻辑，以及向数据库中添加数据的方法。如果您有其他问题或需要进一步的帮助，请随时提问。
英文:
How to update a recyclerview item it its already exists, in shoping cart system? when i add an item 2 times then if i delete one then the second one will appear ,only after deleting the first one in android studio using java
... CartModel cart = new CartModel(namee, manufacture, avail_cart, e__pnum, m__pnum, String.valueOf(p), quantityy, String.valueOf(roundoff));
if (db.addToCart(cart)) {
// Toast.makeText(getApplicationContext(), "Product added to cart " , Toast.LENGTH_LONG).show(); //roundoff
Snackbar.make(findViewById(android.R.id.content),"Product added to cart ",Snackbar.LENGTH_SHORT).show();
} else {
Toast.makeText(getApplicationContext(), "Product not added to cart", Toast.LENGTH_LONG).show();
Snackbar.make(findViewById(android.R.id.content),"Product not added to cart ",Snackbar.LENGTH_SHORT).show();
}
...
public boolean addToCart(CartModel cartModel) {
SQLiteDatabase db = this.getWritableDatabase();
ContentValues values = new ContentValues();
values.put(Manufacturer, cartModel.getManufacturer());
values.put(Availability, cartModel.getAvailability());
values.put(E_part, cartModel.getE_part());
values.put(M_part, cartModel.getM_part());
values.put(Unit_price, cartModel.getUnit_());
values.put(Quantity, cartModel.getQuantity());
values.put(Line_total, cartModel.getLine_total());
values.put(Name, cartModel.getName());
return db.insert(CartDetails, null, values) > 0;
}
答案1
得分: 0
首先，您需要查询数据库，看是否已经存在 cartModel.getName()。如果是，则使用 db.update，否则使用 db.insert。
英文:
First, you need to query the database if cartModel.getName() already exists. If yes, use db.update else use db.insert.
通过集体智慧和协作来改善编程学习和解决问题的方式。致力于成为全球开发者共同参与的知识库，让每个人都能够通过互相帮助和分享经验来进步。
评论