Consider using a SQL database

[altenstedt]

This is an issue for thinking about using a different database than MongoDB.

When we decided on MongoDB, we reasoned that we wanted to use the same database and instance between the Java and C# courses. We also felt that the selection of database was important, and wanted to make a selection that introduced a minimum amount of code complexity.

Several of these assumptions turned out to be flawed. No-one's understanding of the code was impacted by the use of the database. We could also easily have used different databases between Java and C#.

Another aspect is that we want to be able to run the database locally (see #6), so selection of database should be something that can be run locally without cost, and without having to install it (by using docker, for example.)

[erica-edholm]

Rewriting the code for postgres was more work than anticipated. Postponing this issue until next time.

[altenstedt]

Let's do this. We select different databases for C# and Java. Just do it.

We would like to be able to run the database locally, without installations (using Docker.)

It looks like SQL Server is free to use for educational purposes. There is an official Docker image for Linux here:

https://hub.docker.com/_/microsoft-mssql-server

[altenstedt]

As part of this task, we will also create a Docker image for the service. This will simplify running the service, which several students have had issues with.

We will run the two docker images one-by-one (not using docker-compose) since this more clearly shows what is going on.

[altenstedt]

Do not forget to update the README files and welcome email as well. Docker is now a requirement.

[altenstedt]

Running SQL Server using docker is looking promising. Here is the text I have for the README so far:

SQL Server database

You can use the free developer version of SQL Server using docker:

• https://hub.docker.com/_/microsoft-mssql-server

You should read the documentation on Docker Hub above, but something
like the following is probably correct:

docker run -it --rm -e ACCEPT_EULA=Y -e SA_PASSWORD=yourStrongPassword123 -p 1433:1433 mcr.microsoft.com/mssql/server:2017-latest-ubuntu

The resulting connection string would be something like:

Data Source=.;Initial Catalog=tdd2;User Id=sa;Password=yourStrongPassword123;