MongoDB CRUD

This section covers the basics of CRUD opearation including the following:

• 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.
• How to use mongoimport tool to import a JSON file into the MongoDB server – walk you through the steps for how to use the mongoimport tool to import a JSON file into the local MongoDB database server.

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

• $and – show you how to perform a logical AND operator to select documents.
• $or – guide you on how to perform a logical OR operator to find documents.
• $not – learn how to perform a logical NOT operator to query documents.
• $nor – show you how to use the logical NOR operator to select documents.

Section 5. Selecting documents using element query operators

• $exists – select documents where a field exists.
• $type – select documents where the value of a field is an instance of a BSON type.

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 7. Sorting & Limiting

• sort() – show you how to sort returned documents by one or more fields in ascending and descending orders.
• limit() – learn how to specify the number of documents returned by a query.

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.