Postgresql 函数和运算符最多可以接受一组参数错误答案

【问题标题】：Postgresql functions and operators can take at most one set argument errorPostgresql 函数和运算符最多可以接受一组参数错误
【发布时间】：2013-12-04 23:38:33
【问题描述】：

我正在玩 PostGIS，但我不明白这个请求有什么问题？

WITH ligne AS (SELECT 42 AS id, ST_transform('SRID=4326;LINESTRING(2.232 48.818, 2.246 48.82)'::geometry, 27572) AS geom)
SELECT ST_locate_along_measure(ST_addmeasure(geom, 0, ST_Length(geom)), generate_series(0, ST_length(geom)::int, 50)) FROM ligne;

我得到错误：错误：函数和运算符最多可以采用一个集合参数

此请求有效，但我不明白两者之间的区别：

WITH ligne AS (SELECT 42 AS id, ST_transform('SRID=4326;LINESTRING(2.232 48.818, 2.246 48.82)'::geometry, 27572) AS geom),
ligne3dm AS (SELECT ST_addmeasure(geom, 0, ST_Length(ligne.geom)) as geom FROM ligne),
pas50m AS (SELECT generate_series(0, ST_length(ligne.geom)::int, 50) as pas FROM ligne)
SELECT ROW_NUMBER() OVER () AS id, ST_locate_along_measure(ligne3dm.geom, pas50m.pas) FROM ligne3dm, pas50m;

【问题讨论】：

标签： postgresql

【解决方案1】：

解决方案很简单，generate_series 返回一个生成器，但 ST_Locate_Along_Measure 正在等待一个整数。

这将起作用：

WITH ligne AS (SELECT 42 AS id, ST_transform('SRID=4326;LINESTRING(2.232 48.818, 2.246 48.82)'::geometry, 27572) AS geom),
generator AS (SELECT generate_series(0, ST_Length(ligne.geom)::int, 50) as pas FROM ligne)
SELECT ST_locate_along_measure(ST_addmeasure(ligne.geom, 0, ST_Length(ligne.geom)), generator.pas) FROM ligne, generator;

【讨论】：