Mongodb数据处理（备份mongodump、恢复mongorestore、导入mongoimport、导出mongoexport）

转载：http://chenzhou123520.iteye.com/blog/

1.Mongodb自带了mongodump和mongorestore这两个工具来实现对数据的备份和恢复:

mongodump能够在Mongodb运行时进行备份，它的工作原理是对运行的Mongodb做查询，然后将所有查到的文档写入磁盘。但是存在的问题时使用mongodump产生的备份不一定是数据库的实时快照，如果我们在备份时对数据库进行了写入操作，则备份出来的文件可能不完全和Mongodb实时数据相等。另外在备份时可能会对其它客户端性能产生不利的影响。

(1.1).mongodump用法如下：

[root@localhost mongodb]# ./bin/mongodump --helpExport MongoDB data to BSON files.options:  --help                   produce help message  -v [ --verbose ]         be more verbose (include multiple times for more                            verbosity e.g. -vvvvv)  --version                print the program's version and exit  -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  --journal                enable journaling  -d [ --db ] arg          database to use  -c [ --collection ] arg  collection to use (some commands)  -o [ --out ] arg (=dump) output directory or "-" for stdout  -q [ --query ] arg       json query  --oplog                  Use oplog for point-in-time snapshotting  --repair                 try to recover a crashed database  --forceTableScan         force a table scan (do not use $snapshot)

参数说明：

-h:指明数据库宿主机的IP

-u:指明数据库的用户名

-p:指明数据库的密码

-d:指明数据库的名字

-c:指明collection的名字

-o:指明到要导出的文件名

-q:指明导出数据的过滤条件

具体使用示例如下：

[root@localhost mongodb]# ./bin/mongodump -d test -o data/backupconnected to: 127.0.0.1DATABASE: test to data/backup/testtest.system.indexes to data/backup/test/system.indexes.bson 9 objectstest.users to data/backup/test/users.bson 3 objectstest.games to data/backup/test/games.bson 1 objectstest.blog.post to data/backup/test/blog.post.bson 1 objectstest.lists to data/backup/test/lists.bson 1 objectstest.math to data/backup/test/math.bson 1 objectstest.map to data/backup/test/map.bson 8 objectstest.my_collection to data/backup/test/my_collection.bson 0 objectstest.foo to data/backup/test/foo.bson 6 objectstest.system.users to data/backup/test/system.users.bson 1 objects

mongorestore是Mongodb从备份中恢复数据的工具，它主要用来获取mongodump的输出结果，并将备份的数据插入到运行的Mongodb中。

(1.2)mongorestore命令使用方法如下：

[root@localhost mongodb]# ./bin/mongorestore --helpusage: ./bin/mongorestore [options] [directory or filename to restore from]options:  --help                  produce help message  -v [ --verbose ]        be more verbose (include multiple times for more                           verbosity e.g. -vvvvv)  --version               print the program's version and exit  -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  --journal               enable journaling  -d [ --db ] arg         database to use  -c [ --collection ] arg collection to use (some commands)  --objcheck              validate object before inserting  --filter arg            filter to apply before inserting  --drop                  drop each collection before import  --oplogReplay           replay oplog for point-in-time restore  --keepIndexVersion      don't upgrade indexes to newest version

参数说明：

-h:指明数据库宿主机的IP

-u:指明数据库的用户名

-p:指明数据库的密码

-d:指明数据库的名字

-c:指明collection的名字

-o:指明到要备份的文件名

-q:指明备份数据的过滤条件

具体使用示例如下：

[root@localhost mongodb]# ./bin/mongorestore -d test --drop data/backup/test/connected to: 127.0.0.1Tue Aug 14 01:18:17 data/backup/test/games.bsonTue Aug 14 01:18:17  going into namespace [test.games]Tue Aug 14 01:18:17  dropping1 objects foundTue Aug 14 01:18:17 data/backup/test/foo.bsonTue Aug 14 01:18:17  going into namespace [test.foo]Tue Aug 14 01:18:17  dropping6 objects foundTue Aug 14 01:18:17 data/backup/test/blog.post.bsonTue Aug 14 01:18:17  going into namespace [test.blog.post]Tue Aug 14 01:18:17  dropping1 objects foundTue Aug 14 01:18:17 data/backup/test/lists.bsonTue Aug 14 01:18:17  going into namespace [test.lists]Tue Aug 14 01:18:17  dropping1 objects foundTue Aug 14 01:18:17 data/backup/test/map.bsonTue Aug 14 01:18:17  going into namespace [test.map]Tue Aug 14 01:18:17  dropping8 objects foundTue Aug 14 01:18:17 data/backup/test/math.bsonTue Aug 14 01:18:17  going into namespace [test.math]Tue Aug 14 01:18:17  dropping1 objects foundTue Aug 14 01:18:17 data/backup/test/system.users.bsonTue Aug 14 01:18:17  going into namespace [test.system.users]1 objects foundTue Aug 14 01:18:17 data/backup/test/my_collection.bsonTue Aug 14 01:18:17  going into namespace [test.my_collection]Tue Aug 14 01:18:17  droppingTue Aug 14 01:18:17 file data/backup/test/my_collection.bson empty, skippingTue Aug 14 01:18:17 data/backup/test/users.bsonTue Aug 14 01:18:17  going into namespace [test.users]Tue Aug 14 01:18:17  dropping3 objects foundTue Aug 14 01:18:17 data/backup/test/system.indexes.bsonTue Aug 14 01:18:17  going into namespace [test.system.indexes]Tue Aug 14 01:18:17  droppingTue Aug 14 01:18:17 { key: { _id: 1 }, ns: "test.users", name: "_id_" }Tue Aug 14 01:18:17 { key: { _id: 1 }, ns: "test.games", name: "_id_" }Tue Aug 14 01:18:17 { key: { _id: 1 }, ns: "test.blog.post", name: "_id_" }Tue Aug 14 01:18:17 { key: { _id: 1 }, ns: "test.lists", name: "_id_" }Tue Aug 14 01:18:17 { key: { _id: 1 }, ns: "test.math", name: "_id_" }Tue Aug 14 01:18:17 { key: { _id: 1 }, ns: "test.map", name: "_id_" }Tue Aug 14 01:18:17 { key: { gps: "2d" }, ns: "test.map", name: "gps_", min: -180.0, max: 181.0 }Tue Aug 14 01:18:17 { key: { _id: 1 }, ns: "test.foo", name: "_id_" }Tue Aug 14 01:18:17 { key: { _id: 1 }, ns: "test.system.users", name: "_id_" }9 objects found

2.Mongodb数据导出工具mongoexport和导入工具mongoimport介绍:

(2.1)导出工具mongoexport

Mongodb中的mongoexport工具可以把一个collection导出成JSON格式或CSV格式的文件。可以通过参数指定导出的数据项，也可以根据指定的条件导出数据。mongoexport具体用法如下所示：

[root@localhost mongodb]# ./bin/mongoexport --helpExport MongoDB data to CSV, TSV or JSON files.options:  --help                    produce help message  -v [ --verbose ]          be more verbose (include multiple times for more                             verbosity e.g. -vvvvv)  --version                 print the program's version and exit  -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  --journal                 enable journaling  -d [ --db ] arg           database to use  -c [ --collection ] arg   collection to use (some commands)  -f [ --fields ] arg       comma separated list of field names e.g. -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  -k [ --slaveOk ] arg (=1) use secondaries for export if available, default                             true

参数说明：

-h:指明数据库宿主机的IP

-u:指明数据库的用户名

-p:指明数据库的密码

-d:指明数据库的名字

-c:指明collection的名字

-f:指明要导出那些列

-o:指明到要导出的文件名

-q:指明导出数据的过滤条件

实例：test库中存在着一个students集合，集合中数据如下：

> db.students.find(){ "_id" : ObjectId("5031143350f2481577ea81e5"), "classid" : 1, "age" : 20, "name" : "kobe" }{ "_id" : ObjectId("5031144a50f2481577ea81e6"), "classid" : 1, "age" : 23, "name" : "nash" }{ "_id" : ObjectId("5031145a50f2481577ea81e7"), "classid" : 2, "age" : 18, "name" : "james" }{ "_id" : ObjectId("5031146a50f2481577ea81e8"), "classid" : 2, "age" : 19, "name" : "wade" }{ "_id" : ObjectId("5031147450f2481577ea81e9"), "classid" : 2, "age" : 19, "name" : "bosh" }{ "_id" : ObjectId("5031148650f2481577ea81ea"), "classid" : 2, "age" : 25, "name" : "allen" }{ "_id" : ObjectId("5031149b50f2481577ea81eb"), "classid" : 1, "age" : 19, "name" : "howard" }{ "_id" : ObjectId("503114a750f2481577ea81ec"), "classid" : 1, "age" : 22, "name" : "paul" }{ "_id" : ObjectId("503114cd50f2481577ea81ed"), "classid" : 2, "age" : 24, "name" : "shane" }

由上可以看出文档中存在着3个字段：classid、age、name

1.直接导出数据到文件中

[root@localhost mongodb]# ./bin/mongoexport -d test -c students -o students.datconnected to: 127.0.0.1exported 9 records

命令执行完后使用ll命令查看，发现目录下生成了一个students.dat的文件

-rw-r--r-- 1 root root   869 Aug 21 00:05 students.dat

查看该文件信息，具体信息如下：

[root@localhost mongodb]# cat students.dat { "_id" : { "$oid" : "5031143350f2481577ea81e5" }, "classid" : 1, "age" : 20, "name" : "kobe" }{ "_id" : { "$oid" : "5031144a50f2481577ea81e6" }, "classid" : 1, "age" : 23, "name" : "nash" }{ "_id" : { "$oid" : "5031145a50f2481577ea81e7" }, "classid" : 2, "age" : 18, "name" : "james" }{ "_id" : { "$oid" : "5031146a50f2481577ea81e8" }, "classid" : 2, "age" : 19, "name" : "wade" }{ "_id" : { "$oid" : "5031147450f2481577ea81e9" }, "classid" : 2, "age" : 19, "name" : "bosh" }{ "_id" : { "$oid" : "5031148650f2481577ea81ea" }, "classid" : 2, "age" : 25, "name" : "allen" }{ "_id" : { "$oid" : "5031149b50f2481577ea81eb" }, "classid" : 1, "age" : 19, "name" : "howard" }{ "_id" : { "$oid" : "503114a750f2481577ea81ec" }, "classid" : 1, "age" : 22, "name" : "paul" }{ "_id" : { "$oid" : "503114cd50f2481577ea81ed" }, "classid" : 2, "age" : 24, "name" : "shane" }

参数说明：

-d:指明使用的库，本例中为test

-c:指明要导出的集合，本例中为students

-o:指明要导出的文件名，本例中为students.dat

从上面的结果可以看出，我们在导出数据时没有显示指定导出样式 ，默认导出了JSON格式的数据。如果我们需要导出CSV格式的数据，则需要使用--csv参数，具体如下所示：

[root@localhost mongodb]# ./bin/mongoexport -d test -c students --csv -f classid,name,age -o students_csv.datconnected to: 127.0.0.1exported 9 records[root@localhost mongodb]# cat students_csv.dat classid,name,age1.0,"kobe",20.01.0,"nash",23.02.0,"james",18.02.0,"wade",19.02.0,"bosh",19.02.0,"allen",25.01.0,"howard",19.01.0,"paul",22.02.0,"shane",24.0[root@localhost mongodb]# 

参数说明：

-csv：指明要导出为csv格式

-f：指明需要导出classid、name、age这3列的数据

由上面结果可以看出，mongoexport成功地将数据根据csv格式导出到了students_csv.dat文件中。

(2.2)导入工具mongoimport:

Mongodb中的mongoimport工具可以把一个特定格式文件中的内容导入到指定的collection中。该工具可以导入JSON格式数据，也可以导入CSV格式数据。具体使用如下所示：

[root@localhost mongodb]# ./bin/mongoimport --helpoptions:  --help                  produce help message  -v [ --verbose ]        be more verbose (include multiple times for more                           verbosity e.g. -vvvvv)  --version               print the program's version and exit  -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  --journal               enable journaling  -d [ --db ] arg         database to use  -c [ --collection ] arg collection to use (some commands)  -f [ --fields ] arg     comma separated list of field names e.g. -f name,age  --fieldFile arg         file with fields names - 1 per line  --ignoreBlanks          if given, empty fields in csv and tsv will be ignored  --type arg              type of file to import.  default: json (json,csv,tsv)  --file arg              file to import from; if not specified stdin is used  --drop                  drop collection first   --headerline            CSV,TSV only - use first line as headers  --upsert                insert or update objects that already exist  --upsertFields arg      comma-separated 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.

参数说明：

-h:指明数据库宿主机的IP

-u:指明数据库的用户名

-p:指明数据库的密码

-d:指明数据库的名字

-c:指明collection的名字

-f:指明要导入那些列

示例：导入上面导出的students.dat文件中的内容

[root@localhost mongodb]# ./bin/mongoimport -d test -c students students.dat connected to: 127.0.0.1imported 9 objects[root@localhost mongodb]# 

参数说明：

-d:指明数据库名，本例中为test

-c:指明collection名，本例中为students

students.dat：导入的文件名

如果要导入CSV格式文件中的内容，则需要通过--type参数指定导入格式，具体如下所示：

[root@localhost mongodb]# ./bin/mongoimport -d test -c students --type csv --headerline --file students.csvconnected to: 127.0.0.1imported 10 objects[root@localhost mongodb]# 

参数说明：

-type:指明要导入的文件格式

-headerline:指明第一行是列名，不需要导入

-file：指明要导入的文件