在PostGIS中计算一个面要素表中的重叠部分（Find overlaps among polygons in PostGIS）

场景

在PostGIS中有一张面要素表，需要检查该表中的哪些地方有重叠。
其中重叠定义为这些多边形的面状交集。
There is a surface feature table in PostGIS, and it is necessary to check which areas in the table have overlaps.
Overlap is defined as the planar intersection of these polygons.
数据分布如下：

可以直观判断出如下两个区域存在问题：

我们现在来计算出这些区域。

第一步，查找重叠区域

SELECT T1.ID::varchar AS ID1,T2.ID::varchar AS ID2,CASE WHEN T1.ID > T2.ID THEN ST_INTERSECTION(T1.GEOM_COLUMN,T2.GEOM_COLUMN)ELSE ST_INTERSECTION(T2.GEOM_COLUMN,T1.GEOM_COLUMN)END AS GEOMFROM TARGET_TABLE T1 LEFT JOIN TARGET_TABLE T2 ON ST_INTERSECTS(T1.GEOM_COLUMN,T2.GEOM_COLUMN) AND POSITION(''Polygon'' in ST_GEOMETRYTYPE(ST_INTERSECTION(T1.GEOM_COLUMN<