Uploader console app has two functionalities:

• can read investments data from csv file, calculate net and totals. Then store investments in one table and totals in separate table.
• can read investments from database and save it to the csv file

Console app use Entity Framework Core to manage database. To create database you need to execute following commands

Install-Package Microsoft.EntityFrameworkCore.Tools
Add-Migration InitialCreate
Update-Database

for help please have a look here https://docs.microsoft.com/en-us/ef/core/get-started/?tabs=visual-studio