When most people were young, they had someone telling them to "Mind your manners." Such classics as: "Keep your elbows off of the table," "Use a fork," "Put on deodorant," as well as "Don't chew with your mouth open" were bandied about like there were laws of nature. However, manners differ significantly from laws in one crucial way: manners are optional. 

Laws have to be followed, or there are consequences. Drive too fast, and lose your right to drive. Jump off a building, and the law of gravity will teach you a lesson. Conversely, manners are there to help you get along with others. You won't die a horrible, toothless death if you eat your dinner smelling of the day's work with your elbows dug into the table, scooping creamed corn up with your hands into your mouth that you don't close for an entire dinner party (quite an image, right?). You will, however, probably only share one meal with your host.

Manners are those things that are instilled in us as soon as possible in life for us to get along with society. Interestingly, as a computer scientist, it will turn out that manners play a far more significant role in our work than laws ever will. The compiler will generally enforce laws, giving you error messages like every SQL Server programmer's favorite "syntax error near 'a'." 

For the DBA/SQL programmer, we have patterns of development based on engine suitability and working well with other human programmers. The following items all fall under manners, and if you have never seen a seemingly successful database that doesn't mind its manners, then you have led a very sheltered life. 

• Following known database design patterns - No matter the RDBMS you choose, they share a common design pattern set called Normalization that will make life easier when working with data. Other database types have their own patterns. 
• Managing concurrent and isolated execution - it is quite rude to overwrite someone else's data just because you can. Well-mannered programmers make sure their operations are never lossy unless they can be. 
• Formatting code - Most programming languages let you format your code in any way you want, even all on one line. We don't do this because we have the manners not to. 
• Reducing super complex code - Getting carried away as a programmer and trying to be clever is far too easy. Code needs to be only as complicated as it needs to be. Too often, people who think they are clever write code that they can't read 10 minutes later. I know I have!
• Writing reasonable comments - No one likes to write comments, but good programmers realize they are love notes to the next person to touch the code. Often yourself. 

So mind your p's and q's, and work like you are not alone. Someone else may want to work with your database creation and don't leave them a mess. Especially when that next person turns out to be you.