sql - cartodb 在同一层做两次线

Question

我有一个带有 a_route 和 b_route 的数据库。我想在 a_route 具有相同值的所有数据点和 b_route 具有相同值的所有数据点之间划一条线。所以我想拥有：

SELECT ST_MakeLine(the_geom) AS the_geom, a_route
FROM terminals
GROUP BY a_route

和

SELECT ST_MakeLine(the_geom) AS the_geom, b_route
FROM terminals
GROUP BY b_route

在同一层

Answer 1

使用可以使用UNION ALL：

SELECT ST_MakeLine(the_geom) AS the_geom, a_route
FROM terminals
GROUP BY a_route
UNION ALL 
SELECT ST_MakeLine(the_geom) AS the_geom, b_route
FROM terminals
GROUP BY b_route;