To further clarify, the result of a join forms a row that has a new schema . (the new schema is derived from the schemas of the tables participating in the joins.) I would like to retain the old schema in the join result as well, so there is a split between which column belongs / is coming from which table.
Thanks Prakash On Wed, Sep 24, 2014 at 11:03 AM, Prakash Premkumar <prakash.p...@gmail.com> wrote: > Hi, > > Let's say I have tables T1,T2 and T3 with 2 columns each and I am joining > them. > The result rows will have 8 columns each. > > Let's say an output of the join is: > > r11,r21,r31 > r11,r21,r32 > r11,r21,r33 > > where r1i is the i th row in T1, r2i is the i th row in T2 and r3i is the > ith row in T3: > > sqlite produces 3 result rows , but I would like to produce one result row > where, > > r11 > | > r21 > / | \ > r31 r32 r33 > > where the results are linked and the rows r11 and r21 are not repeated.(It > is similar to an adjacency list representation) > > The efficiency I gain with the 2nd approach, is the reduction is in the > number of copies .i.e each row is copied only once. > > Now , I traverse the graph depth first and get the required results as > r11,r21,r31 > r11,r21,r32 > r11,r21,r33 > > are there any hacks in sqlite which does this ? or can you give me some > pointers as in how I should proceed ? I would like to have the linked > output of the join at any point of time and I will traverse the link depth > first to retrieve the individual rows. > > Thanks a lot for your help . > > Prakash > > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
