1.mongodb 数据导出：
connection options:
/h, /host:<hostname> mongodb host to connect to (setname/host1,host2 for replica sets)
/port:<port> server port (can also use --host hostname:port)
authentication options:
/u, /username:<username> username for authentication
/p, /password:<password> password for authentication
/authenticationDatabase:<database-name> database that holds the user's credentials
/authenticationMechanism:<mechanism> authentication mechanism to use
namespace options:
/d, /db:<database-name> database to use
/c, /collection:<collection-name> collection to use
uri options:
/uri:mongodb-uri mongodb uri connection string
output options:
/f, /fields:<field>[,<field>]* comma separated list of field names (required for exporting CSV) e.g. -f "name,age"
/fieldFile:<filename> file with field names - 1 per line
/type:<type> the output format, either json or csv (defaults to 'json') (default: json)
/o, /out:<filename> output file; if not specified, stdout is used
/jsonArray output to a JSON array rather than one object per line
/pretty output JSON formatted to be human-readable
/noHeaderLine export CSV data without a list of field names at the first line
querying options:
/q, /query:<json> query filter, as a JSON string, e.g., '{x:{$gt:1}}'
/queryFile:<filename> path to a file containing a query filter (JSON)
/k, /slaveOk allow secondary reads if available (default true) (default: false)
/readPreference:<string>|<json> specify either a preference name or a preference json object
/forceTableScan force a table scan (do not use $snapshot)
/skip:<count> number of documents to skip
/limit:<count> limit the number of documents to export
/sort:<json> sort order, as a JSON string, e.g. '{x:1}'
/assertExists if specified, export fails if the collection does not exist(default: false)
2.mongodb数据导入：
connection options:
/h, /host:<hostname> mongodb host to connect to
(setname/host1,host2 for
replica sets)
/port:<port> server port (can also use
--host hostname:port)
authentication options:
/u, /username:<username> username for authentication
/p, /password:<password> password for authentication
/authenticationDatabase:<database-name> database that holds the
user's credentials
/authenticationMechanism:<mechanism> authentication mechanism to
use
namespace options:
/d, /db:<database-name> database to use
/c, /collection:<collection-name> collection to use
uri options:
/uri:mongodb-uri mongodb uri connection string
input options:
/f, /fields:<field>[,<field>]* comma separated list of
fields, e.g. -f name,age
/fieldFile:<filename> file with field names - 1 per
line
/file:<filename> file to import from; if not
specified, stdin is used
/headerline use first line in input
source as the field list (CSV
and TSV only)
/jsonArray treat input source as a JSON
array
/parseGrace:<grace> controls behavior when type
coercion fails - one of:
autoCast, skipField, skipRow,
stop (defaults to 'stop')
(default: stop)
/type:<type> input format to import: json,
csv, or tsv (defaults to
'json') (default: json)
/columnsHaveTypes indicated that the field list
(from --fields, --fieldsFile,
or --headerline) specifies
types; They must be in the
form of
'<colName>.<type>(<arg>)'.
The type can be one of: auto,
binary, bool, date, date_go,
date_ms, date_oracle, double,
int32, int64, string. For
each of the date types, the
argument is a datetime layout
string. For the binary type,
the argument can be one of:
base32, base64, hex. All
other types take an empty
argument. Only valid for CSV
and TSV imports. e.g.
zipcode.string(),
thumbnail.binary(base64)
ingest options:
/drop drop collection before
inserting documents
/ignoreBlanks ignore fields with empty
values in CSV and TSV
/maintainInsertionOrder insert documents in the order
of their appearance in the
input source
/j, /numInsertionWorkers:<number> number of insert operations
to run concurrently (defaults
to 1) (default: 1)
/stopOnError stop importing at first
insert/upsert error
/mode:[insert|upsert|merge] insert: insert only. upsert:
insert or replace existing
documents. merge: insert or
modify existing documents.
defaults to insert
/upsertFields:<field>[,<field>]* comma-separated fields for
the query part when --mode is
set to upsert or merge
/writeConcern:<write-concern-specifier> write concern options e.g.
--writeConcern majority,
--writeConcern '{w: 3,
wtimeout: 500, fsync: true,
j: true}'
/bypassDocumentValidation bypass document validation
示例：
mongoexport.exe -h 127.0.0.1 -u admin -p xxx -d test -c user -o user.json --type=json
mongoimport.exe -h 127.0.0.1 -u admin -p xxx -d test_bak -c user --file=dm_task.json --type=json
示例：
mongoexport.exe -h 127.0.0.1 -u admin -p xxx -d test -c user -o user.csv --type=csv --fields="_id,username,birthday,gender,email,phone"
mongoimport.exe -h 127.0.0.1 -u admin -p xxx -d test -c user_bak --file=user.csv --type=csv --headerline
mongoexport 在不指定输出的情况下输出到stdout，mongoimport不指定输入的情况下从stdin读入数据；所以可以配套使用而不需要本地转储；
示例：
mongoexport.exe -h 127.0.0.1 -u admin -p xxx -d test -c user | mongoimport.exe -h 127.0.0.1 -u admin -p xxx -d test_bak -c user
注意：在数据这个过程中可能会出现因为数据量太大导致连接超时拒绝连接；需要记住数据的位置；然后再第二次导入的时候使用skip跳过已经导过的数据；
示例：
mongoexport.exe -h 127.0.0.1 -u admin -p xxx -d test -c user --skip=234567|mongoimport.exe -h 127.0.0.1 -u admin -p xxx -d test_bak -c user
TIPS:本机性能较好，较空闲的话，可以多开几个线程进行数据操作使用-j 参数；
示例：
mongoexport.exe -h 127.0.0.1 -u admin -p xxx -d test -c user --skip=234567|mongoimport.exe -h 127.0.0.1 -u admin -p xxx -d test_bak -c user -j 4
