这似乎可以解决问题，并在PostgreSQL 9.1上进行了测试。几乎肯定会需要对它进行调整以使其适合SQL
Server（任何人都可以随时更新我对此的回答）。

SELECT start AS state,
    SUM((dest = 'MA')::INT) AS MA,
    SUM((dest = 'NJ')::INT) AS NJ,
    SUM((dest = 'NY')::INT) AS NY,
    SUM((dest = 'OH')::INT) AS OH
FROM (
    SELECT state1 AS start, state2 AS dest
        FROM routes
    UNION ALL
    SELECT state2 AS start, state1 AS dest
        FROM routes
) AS s
GROUP BY start
ORDER BY start;

但是请注意，我的输出与您的输出略有不同-我不确定这是因为您的示例输出是错误的，还是因为我误解了您的要求：

 state | ma | nj | ny | oh 
-------+----+----+----+----
 MA    |  0 |  0 |  1 |  1
 NJ    |  0 |  0 |  1 |  0
 NY    |  1 |  1 |  0 |  0
 OH    |  1 |  0 |  0 |  0
(4 rows)

此查询的工作方式是查询表两次，一次查询state1-> state2路由，第二次查询state2-> state1路由，然后将它们连接在一起UNION ALL。

然后，对于每个目标状态，它SUM()为该行的原始状态运行一个。

该策略应易于适应任何RDBMS。