mongodb

This course provides a practical introduction to MongoDB, a leading NoSQL document database. You will learn how to set up a local MongoDB environment using Docker and then dive into essential database operations. By the end of this course, you will know how to:

- Create and manage MongoDB collections.
- Insert, filter, update, and delete documents.
- Perform complex queries using logical operators and expressions.
- Manipulate data within arrays and nested fields.
- Rename fields and manage date and time properties.
- Execute multiple operations efficiently using bulk operations.

Effectively manage and interact with MongoDB databases. Being proficient with databases is a crucial skill in modern app development.

Get started with MongoDB and Docker really quick 🔥 even if you have no backend/fullstack experience.

This lesson guides you through installing Docker Desktop and setting up a MongoDB image.

We explain Docker images and containers, and their roles in providing isolated software environments.

We run a MongoDB image in 2 ways: using the terminal and Docker Desktop

We demonstrates configuring port settings for a container and accessing the MongoDB shell (`mongosh`) to interact with the database.

We learn how to manage Docker containers, configure settings, and run commands inside the container.

Grab the CLI command: 🔥 `docker run --name some-mongo -d mongo:latest` 🔥

Install Docker to run local MongoDB Container

In this lesson, we learn that MongoDB Compass is a graphical user interface for managing MongoDB databases.

We cover how to download and install Compass, create a connection to our local MongoDB instance, and troubleshoot any connection errors.

Additionally, we explore how to navigate the interface to view collections and documents easily.

This lesson provides a practical understanding of using Compass for MongoDB database management.



Access Mongo databases from MongoDB Compass

In this lesson, we learn that creating a MongoDB collection can be done easily through MongoDB Compass or the Mongo shell: `mongosh`.

We cover how to use the GUI to add a new collection and understand that there’s no need for a predefined schema, allowing us to store documents with varying structures.

We also discuss how to remove a collection when it’s no longer needed, demonstrating both methods for flexibility in managing our database.

We also see `find`, `countDocuments` and `drop` MongoDB collection methods in action!


Create or Remove MongoDB Collection

In this lesson, we learn that inserting documents into a MongoDB collection can be done using the `insertOne` and `insertMany` methods.

We demonstrate how to create new employee objects in JSON format and add them to a collection.

We also show how to view the inserted documents and their automatically generated IDs.

Furthermore, we discuss how to delete documents from a collection using filtering criteria.


Inserting Documents into MongoDB Collections (insertOne, insertMany)

In this lesson, we learn that filtering documents from MongoDB collections can be achieved through the `find` and `findOne` methods.

We demonstrate how to use these methods to retrieve documents based on specific criteria, such as names or emails, and how to apply regular expressions for more general searches.

Additionally, we explore filtering by array values and using conditions like less than or greater than for numerical properties.


Filtering Documents in MongoDB Collections (find, findOne)

In this lesson, we learn that combining multiple criteria in MongoDB queries can be done using logical operators such as `$and` and `$or`.

We demonstrate how to create queries that filter documents based on various conditions, such as _age_ and _skills_.

Additionally, we explore the use of the `$in` operator for matching any values in an array and the `$all` operator for ensuring all specified values are present.

This lesson provides essential skills for effective use of operators such as: `$in`, `$nin`, `$lt`, `$lte`, `$gt`, `$gte`, `$eq`, `$ne` (and many others) in querying MongoDB collections.



Combine Filtering Documents in MongoDB Collections ($and, $or, $in, $eq, etc)

In this lesson, we learn that we can perform advanced filtering in MongoDB by using expressions within our queries. All thanks to `$expr`.

We demonstrate how to compare multiple document properties, such as ensuring age is less than salary using comparison operators (`$lt`, `$lte`, `$gt`, `$in`, `$nin`, etc).

Additionally, we explore filtering based on the length of an array (`$size`) to check for specific skills.


Filtering Documents using Expressions in MongoDB Collections ($expr, $size, $in, $and, etc)

In this lesson, we learn that searching for a MongoDB document by its ID can be a little tricky in the beginning.

We demonstrate how to use the `_id` field to search for specific documents and emphasize the necessity of wrapping the ID with the `ObjectId` constructor. This step is crucial because failing to do so can result in empty results, underscoring the importance of proper syntax when querying by document ID.


Find Document by id in MongoDB Collections

In this lesson, we learn that counting documents that meet certain criteria in MongoDB can be done with the countDocuments() method.

We demonstrate how to retrieve the total number of documents when no query is specified and how to filter results using regular expressions.

For example, we can count employees with names containing a lowercase "a" or those with specific skills, using `$regex`.

Additionally, we show how to count documents where age is not equal to a given value, illustrating the versatility of the `countDocuments()` method in various scenarios.


Count documents satisfying a query in MongoDB Collection (countDocuments, $regex, $in)

In this lesson, we learn that when querying MongoDB collections, we can control which properties are returned by using projections with the `findOne` method.

We demonstrate how to include or exclude fields by setting them to 1 or 0, respectively. For example, we can choose to include the name and position while excluding the `_id` field.

We also cover how to access nested properties and project specific elements from arrays using the `$slice` operator, allowing for more precise data retrieval based on our needs.

Return a subset of properties of a MongoDB Document (projections, $slice)

In this lesson, we learn that the Mongosh Cursor is a data structure used by MongoDB to execute queries and manage result sets.

We cover how to sort results using the sort() method, specifying ascending or descending order based on properties like salary.

Additionally, we demonstrate how to limit the number of documents returned with the limit() method and count the size of the result set using count().

We also explore nested sorting by multiple properties, such as salary and age, to refine our query results further.

Perform simple operations on resultset using Mongosh Cursor

In this lesson, we learn that updating documents in MongoDB involves using the `updateOne` and `updateMany` methods along with operators like `$set` and `$unset`.

The `$set` operator allows us to modify existing properties or add new ones, even in nested structures, while the `$unset` operator removes specified properties from a document.

We demonstrate how to use these operators to change a document's salary, modify nested personal information, and remove fields like position.

We also show how to combine `$set` and `$unset` in a single operation for efficient data management.


Update Mongo Documents using updateOne, updateMany, $set and $unset operations

In this lesson, we learn that updating arrays within MongoDB documents involves using the `$push` and `$pull` operators.

The `$push` operator allows us to add new items to an array, while combining it with the `$each` operator enables us to add multiple items simultaneously.

We demonstrate how to add "Java" and ".Net" to the skills array.

Conversely, the `$pull` operator removes elements from an array, and we can use the in operator with `$pull` to remove multiple items, such as "Python" and "SQL," based on specified criteria, providing flexibility in array manipulation.

Update Mongo Documents arrays using $push, $pull and $each operations

In this lesson, we learn that renaming fields in MongoDB documents can be accomplished with the `$rename` operator.

We demonstrate how to use the `updateOne` method to target a specific document, such as one with the name "Bob Johnson."

By specifying the old field names and their new counterparts, like changing position to title and skills to competence, we can effectively update our document structure.

Rename fields in MongoDB Documents

In this lesson, we learn that we can store datetime properties in MongoDB documents using the `$currentDate` operator.

We demonstrate how to create a new date property for a document, such as one for "Bob Johnson," by simply applying the operator.

We also show how to update multiple properties at once and set them as either Date or timestamp types.

By using `$currentDate`, we can easily manage and modify date-related information in our MongoDB documents, ensuring accurate time tracking.

Create or Modify Datetime properties using $currentDate in MongoDB

In this lesson, we learn that replacing a document in a MongoDB collection is done using the `replaceOne` method, which does **not** have a _replaceMany_ equivalent.

We demonstrate how to search for a specific document, such as one with the name "Alice Smith," and replace it with a new document containing updated information like "John Doe."

This operation completely removes all existing fields from the original document and replaces them with those in the new document. After running the operation, we verify that only the new data remains in the collection.


Replace Documents in MongoDB Collections using replaceOne

In this lesson, we learn that upserting in MongoDB allows us to **update a document if it exists** or **insert a new one if it does not**.

We demonstrate how to use the `updateOne` method with the `upsert` flag set to true, which enables us to create a new document for "Kill Bill" with specified skills and age when no matching document is found.

Additionally, we explore using `replaceOne` for similar functionality, confirming that a new document is created when attempting to replace one that does not exist.

This operation simplifies database interactions by combining update and insert actions into a single command.


Upsert Documents in MongoDB Collections using updateOne and replaceOne

In this lesson, we learn that deleting documents from MongoDB collections is straightforward with the `deleteOne` and `deleteMany` methods.

We demonstrate how to use `deleteOne` to remove a specific document based on its salary, confirming the deletion by querying the collection afterward.

We also explore the use of `deleteMany` to remove multiple documents that meet specified criteria, such as salaries greater than a certain amount.

Finally, we illustrate how to clear an entire collection by executing `deleteMany` with an empty query, resulting in the removal of all documents within the collection.

Delete Documents in MongoDB Collections using deleteOne and deleteMany

In this lesson, we learn that to execute multiple requests to a MongoDB server efficiently, we can use **bulk operations**.

We start by initializing a bulk operation that can be either ordered or unordered: `initializeOrderedBulOp` or `initializeUnorderedBulOp`

We demonstrate how to add an insertion operation for a document, such as "John Doe," and how to remove another document, "Bob Johnson," from the collection. After executing the bulk operation, we verify the changes made.

Furthermore, we introduce the `bulkWrite` method for a more streamlined approach to performing multiple operations in one command, allowing us to specify each operation's details explicitly while managing both insertions and deletions effectively.



Get Started with MongoDB

Tomasz Ducin

Free Community Resource

Free Community Resource

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