Given the previous tables, i am selecting names of kids and their favorite quotes. In terms of speed, efficiency, and database design best practices, which is better? Should i have the actual quote in table kids
or should i开发者_如何学C not have the actual quote but reference its id then do another query to fetch it from quotes
table?
Personally, I find it easier to use ID's, pretty much whenever possible. Imagine needing to change a Lincoln quote and having to disable the foreign keys to do it. Then, when you've updated the quotes table, having to update and re-enable the key on the kids table... I've dealt with that in a legacy system, and I wanted to scream.
But that's just me.
I'd rather go with the quote's reference id than duplicating the favorite_quote
field.
It seems like a waste of space to duplicate what appears to be a thousand+ length varchar field more than once.
Normalization of this structure wouldn't really affect performance, and it may actually speed up queries: those very long quotes are going to cause all kinds of page fragmentation in your kids
table.
Keeping a separate quote
table will make it easier to manage and perform better overall.
EDIT:
To answer the question in the comment, you need a quote_id
field in Kids
to JOIN
on:
SELECT k.Name, q.Favorite_Quote
FROM kids k
LEFT JOIN quotes q
ON q.id = k.quote_id
For me it depends on how the data is being used.
For example if the information is needed on each page like
Hey Timmy, we see you're still 8 and your favorite quote is "Action is the blah blah blah"
Then I would go for a single query, but, if the information was only going to be used on a specific page or you want say a quotes page then use multiple queries.
I hope this helps.
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