$addToSet $each 操作,当数组中有中文时,会插入重复数据,这个是为什么? - V2EX
guguai

$addToSet $each 操作,当数组中有中文时,会插入重复数据,这个是为什么?

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  •   guguai May 19, 2015 4839 views
    This topic created in 4022 days ago, the information mentioned may be changed or developed.
    http://suchj.iteye.com/blog/1491023
    今天也遇到这个问题了,上网搜了搜也没有找到解决方法,所以到这里问问。
    1 replies    2015-05-19 18:28:04 +08:00
    karloku
        1
    karloku  
       May 19, 2015   1
    > db.testbed.update({"_id":ObjectId("555b0d58806a1600d242c861")}, {$set: {"name" : []}});
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    > db.testbed.find(ObjectId("555b0d58806a1600d242c861"));
    { "_id" : ObjectId("555b0d58806a1600d242c861"), "name" : [ ] }
    > db.testbed.update({"_id": ObjectId("555b0d58806a1600d242c861")}, {$addToSet: {"name" : {$each : [ "他", "他", "他", 1, 2, 3, "me", "me"]}}}, true)
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    > db.testbed.find(ObjectId("555b0d58806a1600d242c861"));
    { "_id" : ObjectId("555b0d58806a1600d242c861"), "name" : [ "他", 1, 2, 3, "me" ] }
    > db.testbed.update({"_id": ObjectId("555b0d58806a1600d242c861")}, {$addToSet: {"name2" : {$each : [ "他", "他", "他", 1, 2, 3, "me", "me"]}}}, true)
    WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 1 })
    > db.testbed.find(ObjectId("555b0d58806a1600d242c861"));
    { "_id" : ObjectId("555b0d58806a1600d242c861"), "name" : [ "他", 1, 2, 3, "me" ], "name2" : [ "他", 1, 2, 3, "me" ] }

    tested mongodb-3.0.3


    可能是以前版本的bug. 印象里以前还有过$addToSet w/ $each到一个事先不存在的field时会出现重复.