To retrieve distinct values for a field in MongoDB, you can use the distinct method in the MongoDB shell or in a MongoDB driver.
Here’s an example using the MongoDB shell:
db.collectionName.distinct("fieldName")
Replace collectionName with the name of the collection you want to query and fieldName with the name of the field for which you want to retrieve distinct values.
For example, if you have a collection called users and you want to retrieve distinct values for the city field, you can use the following command:
db.users.distinct("city")
This will return an array of all the distinct values for the city field in the users collection.
You can also add additional query criteria to filter the results. For example, if you only want to retrieve distinct values for the city field where the state field is equal to "CA", you can use the following command:
db.users.distinct("city", { state: "CA" })
This will return an array of all the distinct values for the city field in the users collection where the state field is equal to "CA".
