[TML] Back to the 21st century SQL question.

[Christopher Hilton]

garry.e.ward at worldnet.att.net wrote:
> 
> -------------- Original message from Christopher Hilton <chris at vindaloo.com>: -------------- 
> 
> 
>> Christopher Hilton wrote: 
>>> Short: I want to build a sql database to represent an arbitrary number 
>>> of sectors as described in Book 5 Scouts using the expanded star system. 
>>> Has anyone already done this and if so are you willing to share what you 
>>> came up with? 
>>>
>> On the fourth attempt I came up with a basic structure for describing n 
>> sectors. The structure contains six partially normalized tables: 
>>
>> sector -- 
>> star_system -- 
>>
>> all_star -- 
>> all_gas_giant -- 
>> all_world -- 
>>
>> orbital_body -- 
>>
>> The difficulty that I found was in the orbital_body table which must be 
>> self referential and must be able to reference any object in the 
>> all_(star|gas_giant|world) tables. 
>>
>> +----------------------+ 
>> | orbital_body | 
>> +======================+ 
>> | | 
>> | +------------------+ + 
>> | | all_star | | 
>> | +------------------+ + 
>> | | 
>> | +------------------+ + 
>> | | all_gas_giant | | 
>> | +------------------+ + 
>> | | 
>> | +------------------+ + 
>> | | all_world | | 
>> | +------------------+ + 
>> | | 
>> +----------------------+ 
>>
> Huh?
> 
> OK; I think you may be over analyzing.
> 
> There is no need for an all gas giants table; a gas giant is a world like any other world, why segregate it into its own table?
>

Just a justification: 1. In Traveller gas giants can only have one 
attribute (small or large). 2. In Traveller as in the real world gas 
giants can have moons.

> Being at work, I can't take time to review your SQL, will try to to that tonight, but the tables I've been playing with to try and create a navigation database haven't yet run into a need for self referential entries.
> 

Thanks, you may want to pull it again later. After lunch I should have 
the data domain consistency check stuff in.

-- Chris

-- 
       __o          "All I was doing was trying to get home from work."
     _`\<,_           -Rosa Parks
___(*)/_(*)___________________________________________________________
Christopher Sean Hilton                    <chris | at | vindaloo.com>
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