MongoDB is a widely used NoSQL database that allows easy and flexible storage and retrieval of data. One of the key features of MongoDB is its ability to import and export data, which can be useful for backing up data, migrating data between different systems, or simply moving data to a new MongoDB instance. Data import and export in MongoDB can be done using various tools and methods. In this topic, we are going to explore some of the most common ways to import and export data in MongoDB.
MongoDB import and export tools
MongoDB provides two command-line tools for importing and exporting data: mongoimport and mongoexport. A command-line utility called mongoimport allows importing data from various sources like CSV, JSON, or TSV files.
The syntax for using this utility is as follows:
mongoimport --db [database_name] --collection [collection_name] --file [file_path] --type [file_type]
A command-line utility called mongoexport allows exporting the data from a database to a file in various formats like CSV, JSON, or TSV. The syntax for using this utility is as follows:
mongoexport --db [database_name] --collection [collection_name] --out [output_file_path] --type [file_type]
For example, to import a JSON file called users into a MongoDB collection, we can use the following command:
mongoimport --db mydb --collection users --file /path/to/users.json
Similarly, to export the users collection to a JSON file, you can use the following command:
mongoexport --db mydb --collection users --out /path/to/users.json
Importing data from CSV and compressed files
To import data from a CSV file, we can use the mongoimport tool with the --type csv option. For example, to import data from a CSV file called users.csv into a MongoDB collection called users, we should use the following command:
mongoimport --db mydb --collection users --type csv --headerline --file /path/to/users.csv
In this example, the --headerline option tells mongoimport to use the first line of the CSV file as the field names for the MongoDB documents.
If we want to export only a subset of data from a MongoDB collection, there is a mongoexport tool with the --query option. For example, to export only the documents in the users collection where the age field is greater than or equal to 18, we should use the following command:
mongoexport --db mydb --collection users --query '{"age": {"$gte": 18}}' --out /path/to/filtered_users.json
In this example, the --query option specifies a MongoDB query in JSON format that filters the documents to be exported.
To import data from a compressed file (e.g. a gzip or zip file), you can use the mongoimport tool with the --gzip or --archive option, respectively. For example, to import data from a compressed JSON file called users.json.gz into a MongoDB collection called users, we can use the following command:
mongoimport --db mydb --collection users --gzip --file /path/to/users.json.gz
In this example, the --gzip option tells mongoimport to decompress the file on the fly during the import process.
MongoDB Compass import and export
MongoDB Compass is a graphical user interface for MongoDB that allows us to import and export data. To import or export data using MongoDB we should do the following steps:
| Importing Data | Exporting Data |
|---|---|
| Open MongoDB Compass and connect to your MongoDB instance. | Open MongoDB Compass and connect to your MongoDB instance. |
| Select the database to which you want to import data. | Select the database from which you want to export data. |
| From the left-hand side navigation panel, click on the "Collections" tab and select the collection where you want to import data. | From the left-hand side navigation panel, click on the "Collections" tab and select the collection you want to export. |
| Click on the "Import Data" button located at the top right corner of the screen. | Click on the "Export Collection" button located at the top right corner of the screen. |
| In the "Import Options" window, select the file type you want to import (JSON, CSV, or BSON). | In the "Export Options" window, select the file type you want to export (JSON, CSV, or BSON). |
| In the "File Path" section, click on the "Choose File" button and select the file you want to import. | In the "Export Location" section, specify the location where you want to save the exported file. |
| If you are importing a JSON or CSV file, you can also specify options such as whether or not to use the first row as field names or whether or not to allow for invalid data. | If you are exporting a CSV file, you can also specify options such as whether or not to include header rows or whether or not to export data as ASCII or UTF-8. |
| Finally, click on the "Import" button to start the import process. | Finally, click on the "Export" button to start the export process. |
Note that when exporting data from MongoDB Compass, you can also specify a query to filter the data you want to export. To do this, simply click on the "Query" tab in the "Export Options" window and enter your MongoDB query in JSON format.
There are also many third-party tools available for importing and exporting data in MongoDB, such as Studio 3T, Robo 3T, and MongoDB Connector for BI. These tools often provide additional features and options for data import and export, such as data mapping and transformation.
You can also use a MongoDB driver or library in your preferred programming language to export data from a database programmatically.
Conclusion
To sum up, importing and exporting data from MongoDB is essential for managing data in your applications. MongoDB provides several options for importing and exporting data, including command-line utilities, GUI tools, and programming language drivers. By understanding the basics of importing and exporting data from MongoDB, you can efficiently manage your data and ensure its availability when you need it. So, now in order to apply our new knowledge, let's turn to practice.