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

How many authors published at sigcse in 2010 ?
SELECT DISTINCT COUNT(paper.paperid) FROM paper, venue, writes WHERE paper.year = 2010 AND venue.venueid = paper.venueid AND venue.venuename = 'sigcse' AND writes.paperid = paper.paperid
SELECT DISTINCT COUNT("paper"."paperid") FROM "paper" JOIN "venue" ON "paper"."venueid" = "venue"."venueid" AND "venue"."venuename" = 'sigcse' JOIN "writes" ON "paper"."paperid" = "writes"."paperid" WHERE "paper"."year" = 2010