Database relationships (1 Viewer)

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The Archn00b

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This might seem like a stupid question, but is the general rule for a relationships between fields (one to many specifically) only one relationship per pair of fields? Will it cause problems if you have a field linked to two fields each through a one to many relationship? Thanks!
 
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plog

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Gonna need a more concrete example. I can't really understand the number of relationships and fields you want to use. Use these tables:

TableA
Field1, Field2, Field3, Field4

TableB
Field5, Field6, Field7, Field8

Relationship1 =
Relationship2 =

Fill in the relationship info.
 
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ButtonMoon

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The Archn00b said:
This might seem like a stupid question, but is the general rule for a relationships between fields (one to many specifically) only one relationship per pair of fields? Will it cause problems if you have a field linked to two fields each through a one to many relationship? Thanks!
Click to expand...

No. It's quite common to have attributes subject to several different relationships or to have multiple relationships between the same two entities.

Unfortunately the "relationships" window in Access makes an awful mess of displaying models of that kind. It insists on displaying a copy "shadow" table whenever a table is referenced more than once. If you intend to spend a lot of time on modelling or if you want to produce an ER diagram for sharing with others then use a decent third-party tool rather than try to rely on Access.
 
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The Archn00b

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Like:

Table A Field1 has a one to many relationship with Table B field6
Table A Field1 also has a one to many relationship with Table C field10
 
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ButtonMoon

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The Archn00b said:
Table A Field1 has a one to many relationship with Table B field6
Table A Field1 also has a one to many relationship with Table C field10
Click to expand...

Nothing wrong with that. What matters is that you apply some sound principles in your design process: identifying the business rules, keys, datatypes, Normal Form, and so on.
 
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The Archn00b

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Nothing wrong with that. What matters is that you apply some sound principles in your design process: identifying the business rules, keys, datatypes, Normal Form, and so on.
Click to expand...

Thanks for the advice ButtonMoon. I appreciate it!
 
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