How to store site wide settings in a database?

Question

I'm debating three different approaches to to storing sitewide settings for a web application.

A key/value pair lookup table, each key represents a setting.

• Pros Simple to implement
• Cons No Constraints on the individual settings

A single row settings table.

• Pros Per setting defaults and constraints
• Cons - Lots of settings would mean lots of columns. Not sure if Postgres would have an issue with that

Just hard code it since the settings won't change that often.

• Pros Easy to setup and add more settings.
• Cons Much harder to change

Thoughts on which way to go?

Answer 1

Since your question is tagged with database/sql I presume you'd have no problem accessing an sql table for both lookup and management of settings... Guessing here, but I'd start with a table like:

settingName  value   can_be_null   minvalue maxvalue  description
TheAnswer      42       no            1       100     this setting does...
...

If you think about managing a large number of settings, there's more information you need about each one of them than just their current value.