SDB101 » Select: Query 12
 
Query: For each river, identify the closest city

SELECT C1.Name, R1.Name
FROM CITY C1, RIVER R1
WHERE Distance(C1.Shape,R1.Shape) <= ALL
(SELECT Distance(C2.Shape,R1.Shape)
FROM CITY C2
WHERE C1.Name <> C2.Name)

SELECT C.Name, MIN(Distance(C.hape,R.Shape)) AS "River Closest City"
FROM CITY C, RIVER R
GROUP BY R.Name

Última modificación: Friday, 18 de November de 2005, 17:20