Thanks a lot for your help. I really need to make it clear :(
Yes, this is an Entity Relationship Diagram, using Chen's notation.
The inclusion of field names muddies this a bit - an ERD shouldn't really express this information AFAIK.
I think it's a UML diagram
Related
I have such a childish problem. I have such a class diagram and the main problem is that I have never seen this type of uml class notation. Therefore, at the moment I am at a loss as to what these signs mean. And until I find out, I can't really start doing anything. If someone could explain them, I would be very grateful or direct me to where I can read more about these signs.
This is simply not UML but ERD (Entity Relationship Diagram). See also Wikipedia
As Christophe mentioned, yours is crow's foot notation while Wikipedia is using Chen's. More about the notation above in this SO answer as Geert Bellekens found out.
Today I got a diagram similar to this one. The diagram I got was produced using Visio which I don't have. I haven't seen such a diagram before and its symbols are not clear to me.
I tried to google it and find some explanations about this specific type of diagram, but to no avail.
Could you please tell me what type of diagram it is, and give me some links to sites about it?
Thanks in advance.
Looks like a Unified Modeling Language (UML) diagram, in particular, an Entity Relationship diagram
Looks like Entity relationship diagram
Entity-relationship modeling is a database modeling method, used to produce a type of conceptual schema, often a relational database, and its requirements in a top-down fashion. Diagrams created by this process are called entity-relationship diagrams.
This is a cardinality diagram, and the lines represent one-to-many relationships.
http://www.smartdraw.com/resources/tutorials/cardinality-notations/
it is an ER diagram and google provides enough links
Entity-Relationship Diagram
Thanks to everyone. Using your answers and hints, I finally found out that this specific notation system of ER diagrams is called Barker Notation -- that's the answer to my own question :-)
Yes it is entity relationship diagram. As you have mentioned you don’t have Visio, you can download FREE Visio trial for 60 day. I use Visio to create IT diagrams as it has many great features.
Looking at below UML diagram (decorator pattern), what is the name of relationship between Decorator and component? Is it Association?
The two relationships between Component and Decorator constitute another pattern - Composite.
Decorator is a subtype of Component (rel with triangle)
Decorator aggregates (includes) many Components (rel with diamond)
It allows recursive tree structures to be created. Operations called on the aggregate Decorator are delegated to its contained elements. Hence, in your diagram, the behaviour of Decorator.Operation() is to call Component.Operation() on each of its aggregated Components. Since one or more of thpse could themselves be a Decorator, the call to Operation() propagates through the tree structure.
One is an extension the other one aggregation (that's the one with the small nob at Decorator).
Meaning that a Decorator can contain 0 or more Components.
hth
Mario
It's aggregation. Decorator has many Components.
Aggregation. Easiest way to see the difference is with "to be" and "to have".
An object Component "has a decorator". An object Decorator "is a component".
You are describing an aggregation.
The problem is that this diagram should be reversed from your code or you should get a code from your diagram. Just graphical UML designs are not enough for me.
When I use tools with no code mapping to UML then my modeling is sooner or later horrible !!
I create nice diagrams but except for presentation nobody really use them. I have realized that it was a waste of time for everybody in the team.
I have switched to a professional tool then my project was really used by the team and not only a graphical view used once during a story board.
What surprised me is developers have also corrected my diagrams because at implementation stage what was good in UML was impossible in the code :-)
This is why UML as standalone has no value for me if you use the class diagram. I did this mistake using open source graphical tool but will not do it again !!
extends relationship
I was wondering if any analysts/architects have a solution for the hundreds of CRUD operations I would have to add to nearly every class in my UML diagram.
Do you let each class inherit from a base class that implements the CRUD operations?
Best practices and design patterns about this are very much appreciated!
It is very simple. Don't add them to your diagrams. What value would they add?
The value of UML diagrams should be in explaining complex situations. Important is to decide how much you can eliminate, not how much you can add.
I'd use a stereotype to mark the classes and, if and only if you are going to do code generation, I'd make them extend a base class at the "detailed conception" phase (just before the implementation). But if you're not going to generate code (i.e. if you're not doing MDA and I hope for you you are not), I wouldn't even bother adding the inheritance relation. As Stephan mentioned, the real question is: what are you going to do with this information? What value does it add?
I need some sample UML diagrams for some project of medium complexity. Do you know of anywhere where I can find some? I don't need them for learning UML, but rather to test my application that I work on and that should be able to process UML diagrams.
It would suffice to have Class diagram, Package diagram and Component diagram, but those should all model the same system and should be consistent.
Here's an Oracle paper which contains the design of a Web Store application. This paper has all kinds of UML diagrams that one may want - Class, Component, Sequence, Data Model etc. It may not have package diagrams but, those are trivial.
Look at this site, they have nice examples in the product tutorials:
Enterprise Architect
Maybe you should be more concrete about what format you need... Also, it might be interesting to try out some reverse engineering from existing code.