Pretty much any maintained open-source SQL Editor may be suitable for you.
It really depends if you prefer also to be lightweight:
Squirrel SQL - small footprint, universal (both source and os), actively developed java tool. Visual interface is very basic and not intuitive (like in Access).
Execute query - pretty much the same as squirrel, but not that ...
In our project (Azure hosted dotnet core application) we use EF Core to manage DB migrations.
The setup looks like this:
There's a separate C# project with entities (EF Code First models).
There's a separate C# project with Repositories (EF Core related code), also containing migrations (we don't have tons of these). It's called Infrastructure.AzureSql