MongoDB整库备份与还原以及单个collection备份、恢复方法

mongodb数据库维护离不开必要的备份、恢复操作，而且一般不会出错，所以我们在使用的时候大部分时候使用备份和恢复操作就可以了

 

mongodump.exe备份的原理是通过一次查询获取当前服务器快照，并将快照写入磁盘中，因此这种方式保存的也不是实时的，因为在获取快照后，服务器还会有数据写入，为了保证备份的安全，同样我们还是可以利用fsync锁使服务器数据暂时写入缓存中。

高效开源数据库(mongodb)下载地址：http://www.jb51.net/softs/41751.html

备份前的检查
> show dbs
MyDB 0.0625GB
admin (empty)
bruce 0.0625GB
local (empty)
test 0.0625GB
> use MyDB
switched to db MyDB
> db.users.find()
{ "_id" : ObjectId("4e290aa39a1945747b28f1ee"), "a" : 1, "b" : 1 }
{ "_id" : ObjectId("4e2cd2182a65c81f21566318"), "a" : 3, "b" : 5 }
>

整库备份：
mongodump -h dbhost -d dbname -o dbdirectory
-h：MongDB所在服务器地址，例如：127.0.0.1，当然也可以指定端口号：127.0.0.1:27017
-d：需要备份的数据库实例，例如：test
-o：备份的数据存放位置，例如：c:datadump，当然该目录需要提前建立，在备份完成后，系统自动在dump目录下建立一个test目录，这个目录里面存放该数据库实例的备份数据。

mongodump的官方说明(可通过mongodump --help查看)： 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 ( /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)

整库恢复：
mongorestore -h dbhost -d dbname –directoryperdb dbdirectory
-h：MongoDB所在服务器地址
-d：需要恢复的数据库实例，例如：test，当然这个名称也可以和备份时候的不一样，比如test2
–directoryperdb：备份数据所在位置，例如：c:datadump est，这里为什么要多加一个test，而不是备份时候的dump，读者自己查看提示吧！
–drop：恢复的时候，先删除当前数据，然后恢复备份的数据。就是说，恢复后，备份后添加修改的数据都会被删除，慎用哦！

mongorestore的官方说明(可通过mongorestore --help查看)： 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 ( /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 --oplogLimit arg exclude oplog entries newer than provided timestamp (epoch[:ordinal]) --keepIndexVersion don't upgrade indexes to newest version --noOptionsRestore don't restore collection options --noIndexRestore don't restore indexes --w arg (=1) minimum number of replicas per write

单个collection备份：
mongoexport -h dbhost -d dbname -c collectionname -f collectionKey -o dbdirectory
-h: MongoDB所在服务器地址
-d: 需要恢复的数据库实例
-c: 需要恢复的集合
-f: 需要导出的字段(省略为所有字段)
-o: 表示导出的文件名

mongoexport的官方说明(可通过mongoexport --help查看)： --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 ( /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 --forceTableScan force a table scan (do not use $snapshot)

单个collection恢复：
mongoimport -d dbhost -c collectionname –type csv –headerline –file
-type: 指明要导入的文件格式
-headerline: 批明不导入第一行，因为第一行是列名
-file: 指明要导入的文件路径

mongoimport的官方说明(可通过mongoimport --help查看)： --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 ( /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 16MB.

其他导入与导出操作：

1. mongoimport -d my_mongodb -c user user.dat

参数说明:

-d 指明使用的库, 本例中为” my_mongodb”

-c 指明要导出的表, 本例中为”user”

可以看到导入数据的时候会隐式创建表结构

2. mongoexport -d my_mongodb -c user -o user.dat

参数说明:

-d 指明使用的库, 本例中为” my_mongodb”

-c 指明要导出的表, 本例中为”user”

-o 指明要导出的文件名, 本例中为”user.dat”

从上面可以看到导出的方式使用的是JSON 的样式.