MongoDB集合使用mongoimport导入json，导入的数据顺序和原数据顺序不一致

Question

使用mongoimport导入json格式的数据，导入成功后，集合里的数据顺序不对，一直没有找到问题原因。

相关代码

原数据与导入后的数据

{"_id":{"$oid":"58c284b13a1bb9aa7033801b"},"productId":"201710003","productName":"平衡车","salePrice":1999,"productImage":"pingheng.jpg","productUrl":""}
{"_id":{"$oid":"58c284d7117a2e6599abef5e"},"productId":"201710004","productName":"头戴式耳机-3","salePrice":80,"productImage":"2.jpg","productUrl":""}
{"_id":{"$oid":"58c284e6117a2e6599abef5f"},"productId":"201710005","productName":"小米笔记本","salePrice":3549,"productImage":"note.jpg","productUrl":""}
{"_id":{"$oid":"58c284f4117a2e6599abef60"},"productId":"201710006","productName":"小米6","salePrice":2499,"productImage":"mi6.jpg","productUrl":""}
{"_id":{"$oid":"58e704ef98dab115d336b3f1"},"productId":"201710002","productName":"智能插线板","salePrice":59,"productImage":"6.jpg","productUrl":""}
{"_id":{"$oid":"58e7050398dab115d336b3f2"},"productId":"201710007","productName":"自拍杆","salePrice":39,"productImage":"zipai.jpg","productUrl":""}
{"_id":{"$oid":"58e7050c98dab115d336b3f3"},"productId":"201710008","productName":"小米净水器","salePrice":1999,"productImage":"8.jpg","productUrl":""}
{"_id":{"$oid":"58e7051698dab115d336b3f4"},"productId":"201710009","productName":"IH 电饭煲","salePrice":999,"productImage":"9.jpg","productUrl":""}
{"_id":{"$oid":"58e7052198dab115d336b3f5"},"productId":"201710010","productName":"小米电视4A","salePrice":2099,"productImage":"10.jpg","productUrl":""}
{"_id":{"$oid":"58e7052a98dab115d336b3f6"},"productId":"201710011","productName":"Ear1000","salePrice":1000,"productImage":"11.jpg","productUrl":""}
{"_id":{"$oid":"58e7053298dab115d336b3f7"},"productId":"201710012","productName":"Ear1100","salePrice":1100,"productImage":"12.jpg","productUrl":""}
{"_id":{"$oid":"58e7053c98dab115d336b3f8"},"productId":"201710013","productName":"Ear2000","salePrice":2000,"productImage":"13.jpg","productUrl":""}
{"_id":{"$oid":"58e7054798dab115d336b3f9"},"productId":"201710014","productName":"Ear1600","salePrice":1600,"productImage":"14.jpg","productUrl":""}
{"_id":{"$oid":"58e7055198dab115d336b3fa"},"productId":"201710015","productName":"Ear1200","salePrice":1200,"productImage":"15.jpg","productUrl":""}
{"_id":{"$oid":"58e7057798dab115d336b3fb"},"productId":"201710016","productName":"Ear700","salePrice":700,"productImage":"16.jpg","productUrl":""}
{"_id":{"$oid":"58e7058498dab115d336b3fc"},"productId":"201710017","productName":"小钢炮蓝牙音箱","salePrice":129,"productImage":"1.jpg","productUrl":""}
{"_id":{"$oid":"58e7058d98dab115d336b3fd"},"productId":"201710018","productName":"智能摄像机","salePrice":389,"productImage":"photo.jpg","productUrl":""}

> db.goods.find()
{ "_id" : ObjectId("58c284e6117a2e6599abef5f"), "productId" : "201710005", "productName" : "小米笔记本", "salePrice" : 3549, "productImage" : "note.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58e7051698dab115d336b3f4"), "productId" : "201710009", "productName" : "IH 电饭煲", "salePrice" : 999, "productImage" : "9.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58e7052198dab115d336b3f5"), "productId" : "201710010", "productName" : "小米电视4A", "salePrice" : 2099, "productImage" : "10.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58e7052a98dab115d336b3f6"), "productId" : "201710011", "productName" : "Ear1000", "salePrice" : 1000, "productImage" : "11.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58c284d7117a2e6599abef5e"), "productId" : "201710004", "productName" : "头戴式耳机-3", "salePrice" : 80, "productImage" : "2.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58e7053298dab115d336b3f7"), "productId" : "201710012", "productName" : "Ear1100", "salePrice" : 1100, "productImage" : "12.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58e7053c98dab115d336b3f8"), "productId" : "201710013", "productName" : "Ear2000", "salePrice" : 2000, "productImage" : "13.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58e7055198dab115d336b3fa"), "productId" : "201710015", "productName" : "Ear1200", "salePrice" : 1200, "productImage" : "15.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58c284b13a1bb9aa7033801b"), "productId" : "201710003", "productName" : "平衡车", "salePrice" : 1999, "productImage" : "pingheng.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58e7057798dab115d336b3fb"), "productId" : "201710016", "productName" : "Ear700", "salePrice" : 700, "productImage" : "16.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58e7050c98dab115d336b3f3"), "productId" : "201710008", "productName" : "小米净水器", "salePrice" : 1999, "productImage" : "8.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58e7054798dab115d336b3f9"), "productId" : "201710014", "productName" : "Ear1600", "salePrice" : 1600, "productImage" : "14.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58e7058d98dab115d336b3fd"), "productId" : "201710018", "productName" : "智能摄像机", "salePrice" : 389, "productImage" : "photo.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58e7058498dab115d336b3fc"), "productId" : "201710017", "productName" : "小钢炮蓝牙音箱", "salePrice" : 129, "productImage" : "1.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58e704ef98dab115d336b3f1"), "productId" : "201710002", "productName" : "智能插线板", "salePrice" : 59, "productImage" : "6.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58e7050398dab115d336b3f2"), "productId" : "201710007", "productName" : "自拍杆", "salePrice" : 39, "productImage" : "zipai.jpg", "productUrl" : "" }
{ "_id" : ObjectId("58c284f4117a2e6599abef60"), "productId" : "201710006", "productName" : "小米6", "salePrice" : 2499, "productImage" : "mi6.jpg", "productUrl" : "" }

Answer 1

使用数据库的时候，如果你希望得到什么样的顺序，在查询的时候就应该指定排序。如果不指定排序条件，数据库就是以它认为最高效的方式给你返回数据，不保证顺序，也不保证每次出来的顺序是一致的。这一点上几乎所有数据库都是一样的。
所以你原来的数据是什么顺序？为什么这个顺序对你这么重要？如果它这么重要，那你就应该指定排序，比如.sort({_id: 1})