Data export in MongoDB

1. there is a data export tool under the bin directory of the mongodb installation directory: Export export.exe. We can open a command window, switch to this directory, and execute export, you can see many parameter descriptions for using this tool.

Assume that the mongodb installation directory is D: \ program \ mongodb, you can use the export tool in the following ways:

>D:

>D: \ program \ mongodb \ bin

>Mongoexport

-- Help produce help message
-V [-- verbose] be more verbose (include multiple time
Verbosity e.g.-vvvvv)
-- Version print the program's version and exit

........

 

2. Common data export Methods

First, add a new localdb in MongoDB, create a collection user, and insert some objects.

>Use localdb

>Db. user. insert ({"name": "ming", "age": 2 })

>Db. user. insert ({"name": "lisi", "age": 20 })

 

Then, you can use the following method to export data in the user table. -D indicates the database from which data is exported;-c indicates the set from which data is exported;-o indicates the file to which the exported data is exported.

>Mongoexport-d localdb-c user-o user. dat

 

After the export is successful, open the user. dat file and export the data as follows:

{"_ Id": {"$ oid": "4eed9f9ca939118694cf05e4"}, "name": "ming", "age": 2}
{"_ Id": {"$ oid": "4ef1f3cf3bd18218e6bdfa31"}, "name": "lisi", "age": "20 "}

 

3. Export as a CVS file

If you want to save the data of a specified field in the export set to the CVS file, run the following command:

>Export export-d localdb-c user-f _ id, name -- csv-o user.csv

The exported user. cvs file is as follows:

{"_ Id": {"$ oid": "4eed9f9ca939118694cf05e4"}, "name": "ming "}
{"_ Id": {"$ oid": "4ef1f3cf3bd18218e6bdfa31"}, "name": "lisi "}

 

4. mongoexport parameter list

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 your D 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 primary D 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