Connecting desktop APP directly to DB or through a proxy (WCF)

First of all, I am not a programmer anymore but like to stay in touch with development. I would like to develope a simple system for my teammembers to log their work and additional data. Basically, I need every member to use a desktop app which will basically login to DB and allow to do CRUD operations. I can think of two approaches:

1. Having a desktop app with harcoded (or configurable) db connection string and for every user an account would have to be created. So basically login into the system would mean logging into a database with given usesrname


2. 
   

   Having a desktop app communicating with WCF service that would handle all the database connections, so DB root account could be used with a simple table of users.

   
   
   
   
   1. is apparently much easier as it is basically just connecting to the database but I am not sure about security issue there.
   
   
   
   

Thanks