这是一个“简单”或“切换”CASE语句的教科书示例，以避免代码重复。

SELECT CASE greatest(denver, seattle, new_york, dallas, "san fran")
          WHEN denver      THEN 'denver'
          WHEN seattle     THEN 'seattle'
          WHEN new_york    THEN 'new_york'
          WHEN dallas      THEN 'dallas'
          WHEN "san fran"  THEN 'san fran'
       END AS city, *
FROM   tbl;

第一个在列表中（从左到右）获胜的情况下，一个平局。

你可以用一个大的case语句来实现：

select t.*,
       (case when denver = greatest(denver, seattle, new_york, dallas, sanfran) then 'denver'
             when seattle = greatest(denver, seattle, new_york, dallas, sanfran) then 'seattle'
             when new_york = greatest(denver, seattle, new_york, dallas, sanfran) then 'new_york'
             when dallas = greatest(denver, seattle, new_york, dallas, sanfran) then 'dallas'
             when sanfran = greatest(denver, seattle, new_york, dallas, sanfran) then 'sanfran'
        end) as City                 
from table t;

编辑：
我会在最后把结果作为重点。就像这样：

SELECT name, state, the_geom,
       MAX(CASE WHEN seqnum = 1 THEN favorite_team END) as favorite_team,
       MAX(CASE WHEN favorite_team = 'Arizona Cardinals' THEN cnt ELSE 0 END) as ari,
       MAX(CASE WHEN favorite_team = 'Atlanta Falcons' THEN cnt ELSE 0 END) as atl,
       MAX(CASE WHEN favorite_team = 'Baltimore Ravens' THEN cnt ELSE 0 END) as bal,
       MAX(CASE WHEN favorite_team = 'Buffalo Bills' THEN cnt ELSE 0 END) as buf
FROM (SELECT c.name, c.state, c.the_geom, s.favorite_team, count(*) as cnt,
             ROW_NUMBER() OVER (PARTITION BY c.name, c.state, c.the_geom ORDER BY COUNT(*) desc) as seqnum
      FROM fandom_survey_one s JOIN
           counties c
           ON ST_Intersects(s.the_geom, c.the_geom)
      GROUP BY c.name, c.state, c.the_geom, s.favorite_team
     ) c
GROUP BY name, state, the_geom
ORDER BY name, state