I guess, in a way, I’ve always known this, but it’s only when you actually do something properly that you get to know it. I’ve spent a lot of time creating and manipulating tables, but I generally do it via a GUI.
Today I had to create and manipulate a table on a remote server entirely from the command prompt, so I ended up learning how to alter a table. Quite easy really.
ALTER TABLE table_name ADD column_name datatype
I never said I’d be learning something hard every day.