CREATE TABLE writes (paperid NUMBER, authorid NUMBER)
CREATE TABLE journal (journalid NUMBER, journalname VARCHAR2)
CREATE TABLE keyphrase (keyphraseid NUMBER, keyphrasename VARCHAR2)
CREATE TABLE paper (paperid NUMBER, title VARCHAR2, venueid NUMBER, year NUMBER, numciting NUMBER, numcitedby NUMBER, journalid NUMBER)
CREATE TABLE cite (citingpaperid NUMBER, citedpaperid NUMBER)
CREATE TABLE paperkeyphrase (paperid NUMBER, keyphraseid NUMBER)
CREATE TABLE field (fieldid NUMBER)
CREATE TABLE author (authorid NUMBER, authorname VARCHAR2)
CREATE TABLE paperdataset (paperid NUMBER, datasetid NUMBER)
CREATE TABLE paperfield (fieldid NUMBER, paperid NUMBER)
CREATE TABLE venue (venueid NUMBER, venuename VARCHAR2)
CREATE TABLE dataset (datasetid NUMBER, datasetname VARCHAR2)

who published the most at chi
SELECT DISTINCT COUNT(DISTINCT paper.paperid), writes.authorid FROM paper, venue, writes WHERE venue.venueid = paper.venueid AND venue.venuename = 'chi' AND writes.paperid = paper.paperid GROUP BY writes.authorid ORDER BY COUNT(DISTINCT paper.paperid) DESC
SELECT DISTINCT COUNT(DISTINCT "paper"."paperid"), "writes"."authorid" FROM "paper" JOIN "venue" ON "paper"."venueid" = "venue"."venueid" AND "venue"."venuename" = 'chi' JOIN "writes" ON "paper"."paperid" = "writes"."paperid" GROUP BY "writes"."authorid" ORDER BY COUNT(DISTINCT "paper"."paperid") DESC