On Apr 20, 2007, at 5:43 PM, Vladimir Zelinski wrote:
This looks like more table design problem than
database limitation.
The one column should accommodate values from both
columns with unique index built on this column. Your
requirements tell me that these values are the same
nature and should be placed in the same column. To
distinguish between them use another column to put an
attribute.
No, both values can be present at once. They're both external facing
guids that point to the same resource and serve as keys for the table
data. Some rows have one, some have two.
in regards to table desgin solution, if I redid anything it would be
something like:
table_main
main_id
table_main_2_guid
main_id
guid_id unique
context_id
but then i'm using 2 tables and have to join -- which means I need to
rewrite evertyhing that queries this table - which is both the core
table for my application and supposed to be free of any multi-table
queries for simple reads.
so i'm going to try the trigger route.
// Jonathan Vanasco
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