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Apr 12th, 2009
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Database Design Question

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Hello everyone,
I have a fairly simple question about database design. I have a database for county voting equipment. Each county has multiple pieces of voting equipment. I currently have two tables, one with counties and one with voting equipment. Is there any reason to have a relational table between them or is it sufficient to have a county ID field in the equipment table and link them that way. Is there any pro to having a intermediate table between counties and equipment? Any drawback with linking them directly?

Thanks in advance.
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wblakenc is offline Offline
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Apr 12th, 2009
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Re: Database Design Question

Posted this in the wrong area... Sorry!

I know this should be in the database design area, however I was too quick to select MySQL as that is what I am using.
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wblakenc is offline Offline
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Apr 13th, 2009
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Re: Database Design Question

Since the relationship between the tables is a one-to-many relationship, you do not need an intermediate table. You only need to have the following structure:

County: ID (PK), Name, etc.
Voting Equipment: ID (PK), County ID (FK), type, etc.

If counties shared machines so that a machine can be used by more than one county, then you would need an intermediate table. The reason is because you would then have a many-to-many relationship, which requires a independent table showing how the two entities are related.
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timothybard is offline Offline
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Apr 14th, 2009
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Re: Database Design Question

you do not need an intermediate table only defining the relationship by PK and FK will do that for you. But from your post i am not use what exactly you are looking for. I think you need to pass more information.
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debasisdas is offline Offline
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Apr 14th, 2009
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Re: Database Design Question

Perfect! This is what i was thinking, but just wanted to make sure I fully understood why and when I would need an intermediate table.

Thanks again for the help.!
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