I am trying to find the nearest line to each point in a layer, and I have over 1 million points. I want to be able to associated the closest unique line ID with the point unique IDs. I have tried to use the solution given in this post How to find nearest neighbors between two tables with point locations in SpatiaLite? on a small subset, and I do get a result table but the distance value is null, and the IDs from the lines that are associated with each point are not the IDs for the closest lines. I am new with SpatialLite and running spatial queries in SQL. I don't really understand the purpose of this statement: WHERE g1.OGC_FID g2.OGC_FID. I have also played around with this line: AND ST_Contains(ST_Expand(g1.geometry,50),g2.geometry) as well as removed it and still get no distance values, even though I am getting an ID. I was wondering if it might be a coordinate system issue but both the points and the lines are in the same system. I am using the QSpatiaLite plugin in QGIS. Can anyone provide some guidance?
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