RubySeque中的Spatial where子句

Question

如何在Ruby Sequel中编写此SQL查询：

SELECT
  polygon.geometry, count(line)
FROM
  polygon, line
WHERE
  st_intersects(line.geometry, polygon.geometry)
GROUP BY
  polygon.geometry

Answer 1

可能有更好的方法，但这是我的解决方案：

DB.from(:polygon, :line)
  .where('st_intersects(line.geometry, polygon.geometry')
  .select('polygon.geometry, count(line)')
  .group_by(:polygon__geometry)

生成的SQL查询（我使用Oracle DB执行此操作但结果应该相同）：

#<Sequel::Oracle::Dataset: "SELECT 'polygon.geometry, count(line)' FROM \"POLYGON\", \"LINE\" WHERE (st_intersects(line.geometry, polygon.geometry) GROUP BY \"POLYGON\".\"GEOMETRY\"">

Answer 2

DB[:polygon, :line].
  select_group(:polygon__geometry).
  select_append{count(line)}.
  where{st_intersects(:line__geometry, :polygon__geometry)}