MySQL Database Schema for role based system?

We are developing a platform for NGOs (N) to get their work done via Individual Volunteers (V) or Volunteers via a C...

Database normalization for School Management System?

I am creating system for a school management system and come up with the attached database schema. Following is ho...

relationships between 3 entities in ER diagram--is a ternary enough or are 2 binaries also needed??

I'm trying to draw an ER diagram for my project management software describing the following. It contains these enti...

How to rollback a specific migration??

I have the following migration file db\migrate\20100905201547_create_blocks.rb How can I specifically rollback that...