HarrySeah Posted November 8, 2016 Share Posted November 8, 2016 (edited) hi, sorry, i have a question to do...but i know how to write in sql query ....however the answer need to write on relational algebra in query is like : SELECT * FROM operation where r='broken' group by pc having count(pc) >1 ; π id,pc,result ( σ r = 'broken' (operation)) like group by and having clasue...i no idea ... i searched on internet still @@ .... isnt the answer like that, i using split/step by step method to do rel 1 = σ r = 'broken' (operation) rel 2 = σ count(pc)>1 γ pc,count(pc) (rel 1)) rel 3 = π id,pc,result (rel 2 ) thanks Edited November 8, 2016 by HarrySeah Link to comment Share on other sites More sharing options...
justsomeguy Posted November 8, 2016 Share Posted November 8, 2016 Your teacher might want you to use specific symbols for group by and having, but there's a similar question asked here: http://www.dbforums.com/showthread.php?1656382-Group-by-amp-Having-in-relational-algebra Link to comment Share on other sites More sharing options...
HarrySeah Posted November 9, 2016 Author Share Posted November 9, 2016 To: justsomeguy thank you so much for help, yes that page i was viewed before ...but that answer quite ... some confusing .. by the way , thanks Link to comment Share on other sites More sharing options...
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