This section covers the basics of CRUD operations, including:
- Adding new documents to a collection
- Selecting documents
- Updating existing documents
- Removing documents from a collection
Section 1. Adding new documents to a collection
- insertOne() – show you how insert a single document into a collection.
- insertMany() – learn how to insert multiple documents into a collection.
Section 2. Selecting documents
- findOne() – show you how to query a single document.
- find() – learn how to query documents from a collection.
- Projection – guide you on how to specify the fields to return in the matching document.
Section 3. Selecting documents using comparison query operators
- $eq – select documents where the value of a field is equal to a specified value.
- $gt – select documents where the value of a field is greater than a specified value.
- $gte – select documents where the value of a field is greater than or equal to a specified value.
- $lt – select documents where the value of a field is less than a specified value.
- $lte – select documents where the value of a field is less than or equal to a specified value.
- $ne – select documents where the value of a field is not equal to a specified value.
- $in – select documents where the value of a field equals any value in an array
- $nin – select documents where the value of a field doesn’t equal any value in an array
Section 4. Selecting documents using logical query operators
Section 6. Querying arrays
- $size – select documents if they have an array field with a specified size.
- $all – select documents that have an array with all elements specified in a query.
- $elemMatch – select documents if the element in the array field matches all the specified queries.
Section 8. Updating documents
- updateOne() – show you how to update a single document that satisfies a condition.
- updateMany() – learn how to update multiple documents that match a condition.
- $inc – increase/decrease field values
- $min – update the value of a field to a specified value if the specified value is less than the current value of the field.
- $max – update the value of a field to a specified value if the specified value is greater than the current value of the field.
- $mul – multiply the value of a field by a number.
- $unset – remove one or more fields from a document.
- $rename – rename a field in a document
Section 9. Deleting documents
- deleteOne() – delete a single document from a collection.
- deleteMany() – delete all documents that match a condition from a collection.