mysql的新手，所以我什至不确定我问的问题是否正确。我正在尝试向if语句添加多个参数。我正在尝试检查两支球队之间的比赛是否是联赛。SELECTvisitorASschool,homeAStemp,vl.leagueidASvleague,hl.leagueidAShleague,if(vl.leagueid=hl.leagueid,1,0)ASleaguematchFROMscheduleLEFTJOINschoolsASvlONvl.id=visitorLEFTJOINschoolsAShlONhl.id=homeWHEREgamedatebetween'2013-01-01'AN