SQL:指向矩形的点列表

Question

我有两个表:

regions <id>
points <region_id, x, y>

假设每个区域正好有 4 个点，这些点描述了一个矩形——是否有一个 SQL 查询会给我带来这个 View :

rectangular_regions <region_id, x1, y1, x2, y2>

?

Answer 1

SELECT region_id, MIN(x) AS x1, MIN(y) AS y1, MAX(x) AS x2, MAX(y) AS y2 
FROM points 
GROUP BY region_id.