Re: Entity with 1to1, 1toM and MtoM relationships
Posted by: Rick James
Date: July 11, 2013 09:30PM

1:many -- put an id of the 1 in the 'many' entity.
many:many -- build another table with pairs of ids.
1:1 -- usually ill-advised; but you could think of it as 1:many.

http://forums.mysql.com/read.php?10,588719 (Problem creating table with 2 primary keys)
http://forums.mysql.com/read.php?10,568216 (Lookup Table with Optional Fields? Null primary key for blanks?)

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Re: Entity with 1to1, 1toM and MtoM relationships
July 11, 2013 09:30PM


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