qgis topology checker

topology_checker

how-to-find-all-points-within-polygon-in-postgis

postgis-st-within-and-a-join

plugins_geometry_checker

https://postgis.net/workshops/postgis-intro/joins.html

how-to-find-points-within-a-polygon-in-postgis

qgis-db-manager-load-new-layer-not-loading-sql-query