PostGIS错误:无法选择最佳候选函数 [英] PostGIS Error: Could not choose a best candidate function

问题描述

创建视图时，出现错误function populate_geometry_columns(unknown) is not unique.我正在阅读的书使用了此书，但它给了我一个错误.对我来说可能是哪里出了问题?

When creating a View, I get the error function populate_geometry_columns(unknown) is not unique. A book that I'm reading used this, but its giving me an error. What could have gone wrong for me?

查询:

CREATE OR REPLACE VIEW ch03.vw_paris_points AS
SELECT gid, osm_id, ar_num, geom,
tags->'name' As place_name,
tags->'tourism' As tourist_attraction
FROM ch03.paris_hetero
WHERE ST_GeometryType(geom) = 'ST_Point';

SELECT populate_geometry_columns('ch03.vw_paris_points');

错误:

ERROR:  function populate_geometry_columns(unknown) is not unique
LINE 1: SELECT populate_geometry_columns('ch03.vw_paris_points');
               ^
HINT:  Could not choose a best candidate function. You might need to add explicit type casts.

********** Error **********

ERROR: function populate_geometry_columns(unknown) is not unique
SQL state: 42725
Hint: Could not choose a best candidate function. You might need to add explicit type casts.
Character: 8

推荐答案

摘录自精美手册 :

简介

text Populate_Geometry_Columns(boolean use_typmod=true);
int Populate_Geometry_Columns(oid relation_oid, boolean use_typmod=true);

因此，有两个可能的populate_geometry_columns函数可以用一个参数调用，而没有一个TEXT参数.错误消息告诉您PostgreSQL不知道它是否应该将'ch03.vw_paris_points'字符串隐式转换为boolean或oid.我的大脑建议您使用oid版本:

So there are two possible populate_geometry_columns functions that could be called with one argument and neither has a TEXT argument. The error message is telling you that PostgreSQL doesn't know if it is supposed to implicitly cast your 'ch03.vw_paris_points' string to a boolean or an oid. My human brain suggests that you want the oid version:

SELECT populate_geometry_columns('ch03.vw_paris_points'::regclass);
-- add an explicit cast -------------------------------^^^^^^^^^^

但是PostgreSQL的软件头脑只是看到一个字符串而感到困惑. populate_geometry_columns的单参数形式也许比您正在阅读的书新.

but PostgreSQL's software brain just sees a string and gets confused. Perhaps the single argument form of populate_geometry_columns is newer than the book you're reading.

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