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hello everybody

when designing the erd , let's consider the following case :
we have two entities : (management_board) and (person) , a person can't be a member in more than one management board at once , but he can be a member in management_board_1 in 2011 , and then a member in management_board_2 in 2012 , so , the relation between entities : (management_board) and (person) , is it (one to many) or (many to many) ?

thanks in advance ...
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1 solution

If the management board is one entity and contains the management board and the year, for example (name+year is unique, id is primary key)
managementboard
---------------
id
name
year


and the person references a single management board, for example (managementboardid+name is unique)

person
------
managementboardid (foreign  key to managementboard)
name


then it would be a one-to-many relationship.
   
Comments
Espen Harlinn 22-May-12 18:12pm
   
5'ed!
Wendelius 23-May-12 0:06am
   
Thanks Espen
Prasad_Kulkarni 23-May-12 0:25am
   
Nice +5!

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