问题
When I try to create an index on geometry db.polygons.createIndex({"geometry":"2dsphere"})
, it stops at a certain polygon with the error code 16755. It says it Can't extract geo keys
and Duplicate vertices: 18 and 20
.
So upon further inspection, it seems like this happens when 2 nodes in a polygon are close together, or even duplicates.
I then go manually remove this node in QGIS and re-try the process, only to find there's another polygon with the same issue.
How can I fix this issue without having to repeat the entire process of fixing polygon > uploading to MongoDB > creating index? Is there a way I can find out how many polygons have this issue?
回答1:
I hit a similar problem. I just needed to find the valid records in my dataset (I discarded the records with Duplicate Vertices).
I renamed the collection -
db.myCollection.renameCollection('myCollectionBk')
Then I added a single record from the original collection into a new collection and added a geospatial index to the collection
db.myCollection.insert(db.myCollectionBk.findOne()) // recreate the collection
db.myCollection.createIndex({geometry:"2dsphere"}) // create the index (assumes the geometry on the record is valid)
db.myCollection.remove({}) // remove the record
Then I added the valid records into the new collection.
db.myCollectionBk.find().forEach(function(x){
db.myCollection.insert(x);
})
Invalid records are simply ignored.
In your case you probably want to get the WriteResult from your insert, and look to see if it was successful. Something like
var errors = []
db.myCollectionBk.find().forEach(function(x){
var result = db.myCollection.insert(x);
if (result.writeError) {
errors.push({x._id:result.writeError.errmsg});
}
})
As another alternative, check out this question (I couldn't get this to work)
回答2:
So what I did was, I first created the collection with the index and then tried inserting using mongoimport which gave me how many were inserted successfully.
> db.someNewCollection.createIndex({"geometry":"2dsphere"})
To insert GeoJSON into MongoDB I did the following:
$ jq --compact-output ".features" yourGeoJSON > output.geojson
$ mongoimport --db someDB -c someNewCollection --file "output.geojson" --jsonArray
来源:https://stackoverflow.com/questions/36776633/mongodb-error-code-16755-cant-extract-geo-keys-duplicate-vertices