【正文】 jects that already exist upsertFields arg maseparated fields for the query part of the upsert. You should make sure this is indexed stopOnError stop importing at first error rather than continuing jsonArray load a json array, not one item per line. Currently limited to 4MB. 從向MongoDB導出數(shù)據mongoexport d pagedb c page q {} f _id,title,url,spiderName,pubDate csv 說明：，其中各選項含義：f 指定cvs列名為_id,title,url,spiderName,pubDateq 指定查詢條件其他各個選項的使用，可以查看幫助：[plain] view plaincopymongoexport help options: help produce help message v [ verbose ] be more verbose (include multiple times for more verbosity . vvvvv) h [ host ] arg mongo host to connect to ( set name/s1,s2 for sets) port arg server port. Can also use host hostname:port ipv6 enable IPv6 support (disabled by default) u [ username ] arg username p [ password ] arg password dbpath arg directly access mongod database files in the given path, instead of connecting to a mongod server needs to lock the data directory, so cannot be used if a mongod is currently accessing the same path directoryperdb if dbpath specified, each db is in a separate directory d [ db ] arg database to use c [ collection ] arg collection to use (some mands) f [ fields ] arg ma separated list of field names . f name,age fieldFile arg file with fields names 1 per line q [ query ] arg query filter, as a JSON string csv export to csv instead of json o [ out ] arg output file。 if not specified, stdout is used jsonArray output to a json array rather than one object per line 注意：如果上面的選項q指定一個查詢條件，需要使用單引號括起來，如下所示：[plain] view plaincopymongoexport d page c Article q 39。{spiderName: mafengwoSpider}39。 f _id,title,content,images,publishDate,spiderName,url jsonArray 否則，就會出現(xiàn)下面的錯誤：[plain] view plaincopyERROR: too many positional options （六）遠程連接管理基于mongo實現(xiàn)遠程連接[plain] view plaincopymongo u admin p admin :27017/pagedb 通過mongo實現(xiàn)連接，可以非常靈活的選擇參數(shù)選項，參看命令幫助，如下所示：[plain] view plaincopymongo help MongoDB shell version: usage: mongo [options] [db address] [file names (ending in .js)] db address can be: foo foo database on local machine :9999/foo foo database on machine on port 9999 options: shell run the shell after executing files nodb don39。t connect to mongod on startup no 39。db address39。 arg expected quiet be less chatty port arg port to connect to host arg server to connect to eval arg evaluate javascript u [ username ] arg username for authentication p [ password ] arg password for authentication h [ help ] show this usage information version show version information verbose increase verbosity ipv6 enable IPv6 support (disabled by default) 基于MongoDB支持的javascript實現(xiàn)遠程連接當你已經連接到一個遠程的MongoDB數(shù)據庫服務器（例如，），現(xiàn)在想要在這個會話中連接另一個遠程的數(shù)據庫服務器（），可以執(zhí)行如下命令：[plain] view plaincopy var x = new Mongo(39。:2701739。) var ydb = (39。pagedb39。)。 use ydb switched to db ydb db ydb () { _id : ObjectId(4eded6a5bf3bfa0014000003), content : 巴黎是浪漫的城市，可是..., pubdate : 20060319, title : 巴黎：從布魯塞爾趕到巴黎, url : } 上述通過MongoDB提供的JavaScript腳本，實現(xiàn)對另一個遠程數(shù)據庫服務器進行連接，操作指定數(shù)據庫pagedb的page集合。如果啟用了安全認證模式，可以在獲取數(shù)據庫連接實例時，指定認證賬號，例如：[plain] view plaincopy var x = new Mongo(39。:2701739。) var ydb = (39。pagedb39。, 39。shirdrn39。, 39。(jkfFS$343$_\=\,.F@339。)。 use ydb switched to db ydb