Database Reference
In-Depth Information
Using lists for ordered, nonunique values
Let's say that we'd like to allow users to share other users' status updates with their own fol-
lowers. For each status update, we'll keep track of the shares, so that we can display them
to the author. Unlike starring a status update, the same user can share the same status up-
date more than once, so we will track shares as discrete events, retaining the order in which
they occurred.
A list column fits this task perfectly. Like sets, lists contain collections of values; but, un-
like sets, values in sets are nonunique and have a stable and defined order.
