Drawing DFD's
13 May 2003, 04:42 PM
#2
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Havn't you done this backwards?
I thought you drew top level, level 1 DFDs before normalisation?
The tool i've been using is Select, that does a lot of the work for you by creating brother/child diagrams etc.
Paul
I thought you drew top level, level 1 DFDs before normalisation?
The tool i've been using is Select, that does a lot of the work for you by creating brother/child diagrams etc.
Paul
13 May 2003, 05:32 PM
#3
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Don't see how Visio could possibly work out the DFDs (ie the data flows, data stores, data processes, and data sources / destinations) solely from an abstract ER diagram. Could you or I, let alone an automated tool?? (Note: the answer is no
)
A few comments:
- its a very 'physical' ER - you don't normally identify the FKs in an ER diagram - they are implied by the relationship lines between the entities
- why a Match Foreign Key on Match? Do you really have a 'pigs-ear' relationship between matches?
- it's not normal to prefix an attribute with the name (or an abbreviation of the name) of the entity ie RefForename should be Forename
- you've got two Team entities!
- Substitution has has got PlayerFK and PlayerID - presumably one is the 'on' player, one is the 'off' player. Need tto name them better
- a Match has many substitutions; a substitution is for one match. So the relationship line is the wrong way round
- don't think CardID on Match is right. There can me more than one card per match and I'd have thought there's some relationship between Card and Player
...time to stop looking further
HTH
Martin
..edit to correct my own observations
[Edited by MartinM - 5/13/2003 5:42:50 PM]
)A few comments:
- its a very 'physical' ER - you don't normally identify the FKs in an ER diagram - they are implied by the relationship lines between the entities
- why a Match Foreign Key on Match? Do you really have a 'pigs-ear' relationship between matches?
- it's not normal to prefix an attribute with the name (or an abbreviation of the name) of the entity ie RefForename should be Forename
- you've got two Team entities!
- Substitution has has got PlayerFK and PlayerID - presumably one is the 'on' player, one is the 'off' player. Need tto name them better
- a Match has many substitutions; a substitution is for one match. So the relationship line is the wrong way round
- don't think CardID on Match is right. There can me more than one card per match and I'd have thought there's some relationship between Card and Player
...time to stop looking further
HTH
Martin
..edit to correct my own observations
[Edited by MartinM - 5/13/2003 5:42:50 PM]
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24 May 2003, 07:41 PM
#11
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Lecture bollox'd me, as he says its static data. So that information will be in the system anyway just to populate the Combo boxes etc
Si
Si
24 May 2003, 07:49 PM
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Agree for Game Type
Strongly disagree for Opposition - surely they're part of match details?
Disagree for Referee - static data stays static for the life of the system (hence why I agree for Game Type). I bet referees don't stay the same for the life of the system (injuries, newly qualified referees, resignations etc)
Venue - maybe static, maybe not. Premier league venues probably static, pub league venues probably not
HTH
Strongly disagree for Opposition - surely they're part of match details?
Disagree for Referee - static data stays static for the life of the system (hence why I agree for Game Type). I bet referees don't stay the same for the life of the system (injuries, newly qualified referees, resignations etc)
Venue - maybe static, maybe not. Premier league venues probably static, pub league venues probably not
HTH
24 May 2003, 09:33 PM
#13
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Opposition isnt static.
id say referees are, as id just have a list in the Db, then just select one.
Venue, tricky as i have cup/europe/league matches so that can maybe throw some errors, support ill have to encourporate someway enter one if needed, or admin function.
Cheers for you help , much appreciated. Changed the ER but not uploaded new gif
Si
id say referees are, as id just have a list in the Db, then just select one.
Venue, tricky as i have cup/europe/league matches so that can maybe throw some errors, support ill have to encourporate someway enter one if needed, or admin function.
Cheers for you help , much appreciated. Changed the ER but not uploaded new gif
Si
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