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Old 11-26-2012, 05:02 AM   #1
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Default Database

Whats the difference between inner join, outer join and union (database point of view).
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Old 01-06-2013, 09:50 AM   #2
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Default Re: Database

Hey,

- An inner join will only select records where the joined keys are in both specified tables.

- A left outer join will select all records from the first table, and any records in the second table that match the joined keys.

- A right outer join will select all records from the second table, and any records in the first table that match the joined keys.

That's something I fished out from someone else, but I know is correct from using it in recent lectures!

Unfortunately I haven't came across the 'UNION' term myself yet (I'm still learning!).

Perhaps this webpage can help:
SQL UNION Operator

Hope this helps to answer your question!

Regards
Owen Ayres
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