Hello Akshay, On Mon, 2010-03-29 at 18:53 +0530, Akshay Mittal wrote: > MySql does not have the set operations-- > "divide" , "intersect" and "minus" --- related queries as opposed to > set operation - "union". Recently I have developed a php > wrapper which could interface with MySql and implement the "divide" , > "intersect" and "minus" features in the same way as "union". For > example: > > select A,B from rel1 minus select A,B from rel2 > > will return the tuples(A,B) that are present in rel1 and not present > in rel2.
I could be wrong but is this not the same as a left join and checking for NULL in the where condition? Kind Regards -- Andrew Hutchings - LinuxJedi - http://www.linuxjedi.co.uk/ Certified MySQL Developer, DBA & Cluster DBA Zend PHP5 Certified Engineer _______________________________________________ Mailing list: https://launchpad.net/~drizzle-discuss Post to : [email protected] Unsubscribe : https://launchpad.net/~drizzle-discuss More help : https://help.launchpad.net/ListHelp
