Question about migrations in ASP.NET Core

I’m taking the ASP.NET Core x Angular course, and every time I want to start up the project, I have to type
sudo docker run -e 'ACCEPT_EULA=Y' -e 'SA_PASSWORD=MyComplexPassword!234' -p 1433:1433 -d microsoft/mssql-server-linux

and then
dotnet ef database update

for the project to run properly. What exactly is going on when I type those commands? I think it has something to do with “rebuilding” the database, but surely big companies with complex databases can’t have their engineers “rebuild” it on their local machines before they work every day. Cheers

AFAIK the image doesn’t persist any data to the host when started this way. So what you get by running the first command is a clean instance of mssql without any data which is quite handy for development purposes. The second command then applies the migrations defined in your sources to the database.