## Name

ST_IsValidDetail — 返回 `valid_detail` 行，说明几何图形是否有效或无效，说明原因和位置。

## Synopsis

`valid_detail ST_IsValidDetail(`geometry geom, integer flags`)`;

## 描述

• 0：使用常用的 OGC SFS 有效性语义。

• 1：考虑某些类型的自接触环（倒壳和倒孔）是有效的。 这也称为“ESRI 标志”，因为这是这些工具使用的有效性模型。 注意，这在 OGC 模型下是无效的。

## 示例

```
--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     |        |

```