The Family Historian API
The fhSQL Module
The fhSQL module is a library of functions to access SQL based databases. You must include a link like this near the start of your plugin:
require("fhSQL");
Thereafter you can call fhSQL functions like this:
local db = fhSQL.connect("Provider=Microsoft.Jet.OLEDB.4.0;Data Source="..dbfile)
Additional examples can be found here.