How to Export MongoDB Database Using Command Line

Introduction to mongoexport

mongoexport is a command-line utility designed to export data from a MongoDB database into a JSON or CSV file format. This tool is essential for database backups, migrations, or processing data with external tools.

Prerequisites

Before using mongoexport, ensure MongoDB is installed and running. The tool requires specifying the target collection within the database for export.

Running mongoexport

Execute the mongoexport command from the system command line, not the mongo shell. Use the --db and --collection options to specify the database and collection, respectively. For example:

mongoexport --db database_name --collection collection_name --out filename.json

Authentication and Security

If authentication is required, use --username and --password options. To enhance security, specify the password in a configuration file with --config rather than on the command line.

For encrypted certificate-key files, use --sslPEMKeyPassword. Be cautious as this may expose the password. Alternatively, use the configuration file method.

To connect over SSL, include the --ssl option. Use --sslCRLFile for specifying a Certificate Revocation List and --sslAllowInvalidCertificates to bypass certificate validation, although this is a security risk.

Export File Customization

Control the export format with the --type option. It can be 'csv' or 'json' depending on the required format. For CSV exports, use --fields or --fieldFile to specify which fields to include.

Filtering and Sorting Data

Utilize --query to export only the documents matching a certain criteria. To order the results, use --sort in conjunction with --skip and --limit to control the exported dataset size. Note that the sorting operation relies on an existing index and the result size must be under 32 megabytes.

Troubleshooting Connection Issues

If you encounter 'cannot unmarshal DNS' errors on systems like Ubuntu 18.04, use the --uri option with a non-SRV connection string, or specify the host and port directly with --host and --port options.

Conclusion

With mongoexport, you can efficiently export data from MongoDB to JSON or CSV files using the command line, allowing for easy data manipulation and storage outside of the database environment.

Frequently Asked Questions

How do I run mongoexport to export data from a MongoDB database?

Use the mongoexport command from the system command line, ensuring you specify the required parameters such as --db for the database, --collection for the collection you wish to export from, and --out to direct the output to a file. If you are using authentication, also include --username and --password options.

Can I export only certain fields from a collection in MongoDB using mongoexport?

Yes, you can export specific fields by using the --fields option followed by a comma-separated list of field names, or you can use the --fieldFile option with a file containing the list of fields.

How do I specify the file format for the exported data using mongoexport?

Use the --type option with either 'json' or 'csv' as the value to specify the file format of the exported data.

How can I filter the data to be exported with mongoexport?

You can filter the data by using the --query option with a JSON document to match the documents you want to export. Make sure to use Extended JSON v2 syntax if the query contains types that aren’t part of standard JSON.

What should I do if I need to sort the exported data or limit the number of documents exported?

To sort the exported data, use the --sort option with a JSON document specifying the sort order. To limit the number of documents, use the --limit option with the desired document count. You can also use the --skip option in conjunction with these to skip a number of documents.

Common Use Cases

• 
  Creating backups of a MongoDB database for disaster recovery scenarios
• 
  Migrating data from one MongoDB server to another
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  Archiving data for compliance with data retention policies
• 
  Sharing datasets with collaborators for development or analysis purposes
• 
  Performing data analysis on exported datasets using separate analytics tools

Why Choose Sourcetable over Traditional MongoDB Exports

For users seeking an intuitive and efficient alternative to command line database exports, Sourcetable offers a seamless solution. Unlike the complex process of exporting MongoDB databases using command line instructions, Sourcetable simplifies data aggregation and manipulation. With its real-time data retrieval and familiar spreadsheet interface, users can bypass the steep learning curve associated with command line operations.

Sourcetable's integration capabilities allow for direct connection to MongoDB, providing a central hub for all your data sources. This eliminates the need for manual exports and conversions, streamlining data workflows. The platform's spreadsheet-like interface is ideal for those who prefer the accessibility and flexibility of spreadsheets for data analysis and management.

With Sourcetable, the focus shifts from the intricacies of data export commands to the ease of data exploration and utilization. By enabling real-time queries and manipulation within its interface, Sourcetable empowers users to interact with their MongoDB data dynamically, fostering a more productive and user-friendly environment for data-driven decision-making.