Tôi đã thử với công cụ "Make Geometries hợp lệ" của OpenJUMP và nó trả về hình học đã được hiệu chỉnh dưới dạng đa giác. OpenJUMP đang sử dụng chức năng makeValid của riêng nó. Tôi không biết nếu QGIS có chức năng tương đương nhưng vì bạn đã có tính năng này trong PostGIS, bạn chỉ cần sử dụng ST_MakeValid http://postgis.net/docs/ST_MakeValid.html .
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