How to properly design a class for working with a database?

Question

Qt

I have been working (for a month now) in a small company, writing a project in C ++ using Qt, SQLite was chosen as the database. There are no higher level programmers nearby.
I decided to design a separate module for working with the database. There are tables in the database: product, seller, sale. In one of the windows of the program, a table into which data from the database will be loaded. You can also create a new entry there. When you click the Save button, changes are saved / a new entry appears if it does not exist.
I already have a DataBase class responsible for connecting to the database, opening/closing the connection, and sending the query string to the database, and so on.
(0) You can add a method to the same class, in whose parameters you need to specify product attributes, for example, for further addition to the database, but there are quite a lot of them, and this does not seem to me a good approach.
You can create separate classes for each of the database tables.
In this case, there are several options:
(1) In each class, create methods that send a query string to the DataBase class, but they will require an object instance. If the database grows, then I think when it is displayed, creating an object for each database entry will significantly slow down the program.
(2) Make these methods static, sending a signal (event), for example, to add a record, which will be received by a slot (method, event handler) of the DataBase class. But then there is a problem with connecting the signal and the slot, because the connect method needs an object instance.
(3) You can make structures instead of classes, but in this case we get a slightly improved version (0).
Which of these should you choose? Or is there some better option?

Answer 1

Surely there is some kind of ready-made ORM for C ++, so as not to reinvent the wheel, but if not, then you need to choose between the Active Record and DataMapper patterns