Info
If a multi:true update is run such that it fails halfway the resulting nModified / nMatched fields appear to always be set to zero (and the appropriate error given) even if documents have been modified.
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david.storch commented on Mon, 29 Aug 2016 14:47:03 +0000:
Closing as a duplicate of SERVER-15292.
Steps to Reproduce
db.test.drop()
db.test.ensureIndex({num:1},{unique:true})
db.test.insert([{num:0},{num:2},{num:4},{num:6},{num:7},{num:10}])
db.test.update({},{$inc:{num:1}},{multi:true})
Gives:
WriteResult({
"nMatched" : 0,
"nUpserted" : 0,
"nModified" : 0,
"writeError" : {
"code" : 11000,
"errmsg" : "E11000 duplicate key error collection: mt.test index: num_1 dup key: { : 7.0 }"
}
})
But...
> db.test.find({},{_id:0})
{ "num" : 1 }
{ "num" : 3 }
{ "num" : 5 }
{ "num" : 6 }
{ "num" : 7 }
{ "num" : 10 }
3 documents were modified. We would expect "nMatched" and "nModified" to be at least 3.
