I really need help with an ERD model I have to create. I'm at my wits end trying to figure out if what I'm doing is right or not. I've attached a .png file with what it looks like. I am not allowed to have many-to-many relationships (so I must create intermediary tables) and "an employee can be assigned to many projects, but only one project per city."
Please let me know if I should post the instructions along with the ERD, but I think the table names render the model fairly self-explanatory. I'm mostly concerned with relationships and the 'Work Details', 'Project Description' and 'Project Assigned..' tables.
Without business rules there is no way to validate that ERD model for you. We could apply our own business rules or rules we think are appropriate, but we could be far off.
"an employee can be assigned to many projects, but only one project per city."
The model now says:
- there can only be one city per project. (another project could be in the same city)
- an employee can be assigned to many projects
Is this correct? Or should it be:
"an employee can be assigned to many projects, but each of those assigned projects must be located in a different city." ?
Last edited by Wim; 04-16-12 at 06:00.
With kind regards . . . . . SQL Server 2000/2005/2012
Grabel's Law: 2 is not equal to 3 -- not even for very large values of 2. Pat Phelan's Law: 2 very definitely CAN equal 3 -- in at least two programming languages