对同一字段(mysql或sqlite3)进行SQL双击选择。

Question

我有一个我不能解决的问题！(sqlite3，但我认为它与MySql相同)我有这些表(图)：

alt text http://www.radarkiller.fr/blog/bddprobleme.png

我想找出去往两条不同街道的所有公交线路(包括类型和编号)，我从这两条街道上有street_id (例如12和14 )。

结果将向客户提供城市中从街道n°12到街道n°14 (例如)的所有公交线路( id、类型和编号)。

就像Larry Lustig说的那样，你可以用两个邻居的外键来创建一个捷径。

提前感谢您的帮助！

Answer 1

使用GROUP BY/COUNTING：

  SELECT t.bus_line_id,
         t.bus_line_type,
         t.bus_line_number
    FROM BUS_LINE t
    JOIN LINK_BUS_NEIGBOURHOOD lbn ON lbn.bus_line_id = t.bus_line_id
    JOIN LINK_NEIGHBOURHOOD_STREET lns ON lns.neighbourhood_id_ns = lbn.neighbourhood_id_ns
    JOIN STREET s ON s.street_id = lns.street_id
   WHERE s.street_id IN (12, 14)
GROUP BY t.bus_line_id,
         t.bus_line_type,
         t.bus_line_number,
         s.street_id
  HAVING COUNT(DISTINCT s.street_id) = 2

使用JOIN：

SELECT t.bus_line_id,
       t.bus_line_type,
       t.bus_line_number
  FROM BUS_LINE t
  JOIN LINK_BUS_NEIGBOURHOOD lbn ON lbn.bus_line_id = t.bus_line_id
  JOIN LINK_NEIGHBOURHOOD_STREET lns ON lns.neighbourhood_id_ns = lbn.neighbourhood_id_ns
  JOIN STREET s ON s.street_id = lns.street_id
               AND s.steet_id = 12
  JOIN STREET s2 ON s2.street_id = lns.street_id
                AND s2.steet_id = 14

Answer 2

假设您希望在示例结果集中有三个单独的记录，并假设所有"neighborhood_id“列都是FK返回到邻居表，请尝试：

SELECT * 
  FROM bus_line 
 WHERE EXISTS (SELECT * 
                 FROM neighborhood N 
           INNER JOIN link_neighborhood_street S ON N.neighborhood_id = S.neighborhood_id_ns 
                WHERE S.street_id = 12) 
  AND EXISTS (SELECT * 
                FROM neighborhood N 
          INNER JOIN link_neighborhood_street S ON N.neighborhood_id = S.neighborhood_id_ns 
               WHERE S.street_id = 14);