ST_IsValidDetail — 返回一个 valid_detail 表示几何图形是否有效或原因和位置是否有效的行。
valid_detail ST_IsValidDetail(geometry geom, integer flags);
返回一个 valid_detail 行，包含一个布尔值( valid )声明几何图形是否有效，则使用varchar( reason )说明无效的原因，以及几何图形( location )指出其无效之处。
有助于改进以下各项的组合 ST_IsValid 和 ST_IsValidReason 以生成无效几何图形的详细报告。
可选的 flags 参数是位字段。它可以具有下列值：
0：使用常用的OGC SFS有效性语义。
1：考虑某些类型的自触环(倒壳和外折孔)有效。这也称为“ESRI标志”，因为这是这些工具使用的有效性模型。请注意，这在OGC模型下是无效的。
由GEOS模块执行。
可用性：2.0.0
--First 3 Rejects from a successful quintuplet experiment
SELECT gid, reason(ST_IsValidDetail(geom)), ST_AsText(location(ST_IsValidDetail(geom))) as location
FROM
(SELECT ST_MakePolygon(ST_ExteriorRing(e.buff), array_agg(f.line)) As geom, gid
FROM (SELECT ST_Buffer(ST_Point(x1*10,y1), z1) As buff, x1*10 + y1*100 + z1*1000 As gid
FROM generate_series(-4,6) x1
CROSS JOIN generate_series(2,5) y1
CROSS JOIN generate_series(1,8) z1
WHERE x1 > y1*0.5 AND z1 < x1*y1) As e
INNER JOIN (SELECT ST_Translate(ST_ExteriorRing(ST_Buffer(ST_Point(x1*10,y1), z1)),y1*1, z1*2) As line
FROM generate_series(-3,6) x1
CROSS JOIN generate_series(2,5) y1
CROSS JOIN generate_series(1,10) z1
WHERE x1 > y1*0.75 AND z1 < x1*y1) As f
ON (ST_Area(e.buff) > 78 AND ST_Contains(e.buff, f.line))
GROUP BY gid, e.buff) As quintuplet_experiment
WHERE ST_IsValid(geom) = false
ORDER BY gid
LIMIT 3;
gid | reason | location
------+-------------------+-------------
5330 | Self-intersection | POINT(32 5)
5340 | Self-intersection | POINT(42 5)
5350 | Self-intersection | POINT(52 5)
--simple example
SELECT * FROM ST_IsValidDetail('LINESTRING(220227 150406,2220227 150407,222020 150410)');
valid | reason | location
-------+--------+----------
t | |