In this lab, create a database, configure a collection, insert documents, and verify that the environment works. You can use Atlas, a local MongoDB server, or Docker.

Step 1: Connect to MongoDB

Connect using mongosh and verify the connection:

db.runCommand({ ping: 1 });

Step 2: Select a dedicated practice database

use mongodb_environment_lab

Step 3: Create a collection with validation

db.createCollection("developers", {
 validator: {
 $jsonSchema: {
 bsonType: "object",
 required: ["name", "email", "experienceYears"],
 properties: {
 name: {
 bsonType: "string",
 minLength: 1
 },
 email: {
 bsonType: "string",
 minLength: 3
 },
 experienceYears: {
 bsonType: ["int", "long", "double", "decimal"],
 minimum: 0
 },
 skills: {
 bsonType: "array",
 items: {
 bsonType: "string"
 }
 },
 location: {
 bsonType: "object",
 properties: {
 city: { bsonType: "string" },
 country: { bsonType: "string" }
 }
 }
 }
 }
 },
 validationLevel: "strict",
 validationAction: "error"
});

Step 4: Insert valid documents

db.developers.insertMany([
 {
 name: "Arun",
 email: "arun@example.com",
 experienceYears: 3,
 skills: ["JavaScript", "Node.js", "MongoDB"],
 location: {
 city: "Chennai",
 country: "India"
 }
 },
 {
 name: "Meera",
 email: "meera@example.com",
 experienceYears: 5,
 skills: ["React", "TypeScript", "MongoDB"],
 location: {
 city: "Bengaluru",
 country: "India"
 }
 }
]);

Step 5: Read and inspect documents

db.developers.find();

db.getCollectionNames();

db.getCollectionInfos();

Step 6: Test validation

Attempt to insert a document missing email:

db.developers.insertOne({
 name: "Invalid Example",
 experienceYears: 2
});

The operation should fail because email is required. Run this only as an intentional validation test in your practice environment.

Step 7: Verify nested data

db.developers.find({ "location.city": "Chennai" });

This query uses dot notation to find developers whose nested city field is Chennai.

Step 8: Count documents

db.developers.countDocuments({});

If both valid documents were inserted successfully and no additional documents were added, the result should be 2.

Step 9: Check environment configuration

If you are using a Node.js application, confirm that the connection string is supplied through the server-side MONGODB_URI environment variable. Verify its presence without printing its value.

Step 10: Clean up if needed

Only if you want to remove this disposable practice collection:

db.developers.drop();

Dropping the collection removes its documents and collection configuration. Do not execute this command against a production collection.

Lab challenges

1. Create another collection called courses.
2. Insert three course documents with different difficulty levels.
3. Find courses with a particular difficulty.
4. Create a validator that requires title and level.
5. Intentionally attempt an invalid insert and explain the error.
6. Explain why a successful ping does not guarantee write permission.
7. Describe how you would prevent a database URI from reaching browser code.
8. Explain how a Docker named volume differs from a container.
9. Identify the first three things you would check after a server selection timeout.
10. Explain why a development database should be separate from production.