StackOverflow2013

Note that there are some explanatory texts on larger screens.

plurals

POUML association vs. composition and detail level
primarykey
Id
6086718
data
AcceptedAnswerId
0
AnswerCount
4
ClosedDate
CommentCount
0
CommunityOwnedDate
CreationDate
2011-05-22T07:48:24.077
FavoriteCount
11
LastActivityDate
2014-02-04T11:50:25.183
LastEditDate
2011-05-22T11:15:35.867
LastEditorUserId
1
OwnerUserId
764602
ParentId
0
PostTypeId
1
Score
16
ViewCount
18636
LastEditorDisplayName
text
Body
Actually, make that a couple of amateur UML questions! When creating a UML diagram to model some domain concepts and you come across a domain concept that "holds" some information about another concept, is it better to hold a stamp/reference to that entity or hold the whole entity in the model itself? Please bear in mind that this is relating to creating a simple high-level model - I'm sure in the implementation stage things would be slightly different. For example, which of the two models below is actually correct? The first one has a composition relationship, with FlightBooking holding the whole of Flight. In the second one, FlightBooking just has a reference to Flight. <img src="https://i.stack.imgur.com/RblwN.png" alt="http://imageshack.us/m/96/2227/flightiu.png"> Secondly, when creating a high level UML diagram modelling domain concepts, how much detail are you really meant to go? For example, in the diagram below, a flight could hold details about origin/destination as strings, or I could model separate classes for these concepts and create a composition relationship. Which of the two is advisable? <img src="https://i.stack.imgur.com/Idffa.png" alt="http://imageshack.us/m/23/3395/flight2s.png"> Also, just another thing, when modelling the above where a Flight "holds" an orig/destination as another class rather than a string, which of the two ways is the correct way of modelling this? I'm quite confused as to when to show assosciation and when to show composition.
Tags
<uml><relationship><composition>
Title
UML association vs. composition and detail level
singulars
PostAcceptedAnswerId
1. This table or related slice is empty.
PostParentId
1. This table or related slice is empty.
PostTypePostTypeId
1. PTQuestion
UserLastEditorUserId
1. USJeff Atwood
UserOwnerUserId
1. USRoger2233
plurals
PostLinksPostIdRelatedPostId
1. PL
 singulars
 LinkTypeLinkTypeId
 LTLinked
PostLinksRelatedPostIdPostId
1. PL
 singulars
 LinkTypeLinkTypeId
 LTLinked
2. PL
 singulars
 LinkTypeLinkTypeId
 LTLinked
PostsAcceptedAnswerId
1. This table or related slice is empty.
PostsParentIdCreationDate
1. PO
 singulars
 PostTypePostTypeId
 PTAnswer
2. PO
 singulars
 PostTypePostTypeId
 PTAnswer
3. PO
 singulars
 PostTypePostTypeId
 PTAnswer
VotesPostIdCreationDate
1. VO
 singulars
 PostPostId
 POUML association vs. composition and detail level
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTModeratorReview
2. VO
 singulars
 PostPostId
 POUML association vs. composition and detail level
 UserUserId
 This table or related slice is empty.
 VoteTypeVoteTypeId
 VTUpMod
3. VO
 singulars
 PostPostId
 POUML association vs. composition and detail level
 UserUserId
 USAndrzej Duś
 VoteTypeVoteTypeId
 VTFavorite
CommentsPostId
1. This table or related slice is empty.

Querying!

Guidance

A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.