if exists(select 1 from usertabel U inner join #tempJobPeopleLeaveTable T on U.username = T.username and U.sex = T.sex where T.id= @id)
begin 
--更新
end 
else 
begin
--添加
end

------解决方案--------------------
@id  是自定义的变量，表示传入的值

------解决方案--------------------
IF EXISTS(select id from #TempJobPeopleLeaveTable where id in (select id
from
userTable) )
  begin
    update userTable(userName ,sex )values(#TempJobPeopleLeaveTable.userName,#TempJobPeopleLeaveTable.sex)
  where #TempJobPeopleLeaveTable.id=userTable.id

else
  begin
    select * from #TempJobPeopleLeaveTable insert into userTable
end

------解决方案--------------------
的确建议使用merge