M Mar5000k Beta member Messages 4 Location Uganda Nov 26, 2012 #1 Whats the difference between inner join, outer join and union (database point of view).
O Owen1 Beta member Messages 2 Location United Kingdom Jan 6, 2013 #2 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
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