Install Gradle using one of the many methods:
https://gradle.org/install/

• Open a terminal, run gradle –version. If it runs, you are good to go.

Create project folder

• Create a folder somewhere as the root folder for your Java …

In blackbox testing, we can use diff command to check an output file against expected results. To check standard output during unit testing, we can use a mock stdout and stderr to capture any outputs.

Using unittest module …

To Bash or not to Bash

Writing shell scripts can automate command execution and help us become more productive. Bash is the default shell for most linux distributions.

Which Bash

Check that your have Bash installed.

$ which bash …

Syntax

grep [OPTION...] PATTERNS [FILE...]
grep [OPTION...] -e PATTERNS ... [FILE...]
grep [OPTION...] -f PATTERN_FILE ... [FILE...]

The grep command takes in text from stdin or a file.

Quick Examples

The lady with the …

Unlike relational databases, there are no native methods for relations in MongoDB. However, we can try to create relations by referencing the _id between documents.

We will continue to use the sample database, sample_supplies, for this demo. In the …

Schema validation

While MongoDB does not enforce data type validation by default, it can be enabled by specifying validation rules when creating a collection.

// Use database: sample_supplies
> use sample_supplies
switched to db …

bulkWrite() method

db.collection.bulkWrite() method can perform these operations:

• insertOne
• updateOne
• updateMany
• replaceOne
• deleteOne
• deleteMany

It has the following syntax:

db.collection(
    [
        {
            <operation1>: { …

Aggregation pipeline stages

Aggregation pipeline is an array of aggregation methods that process data stage-by-stage until a result is returned at the end of the pipeline.

Aggregation pipeline stages for a collection is executed by the …

Managing inventory for an office supply store

Imagine running an office supply company. We need to keep track of customer information, sales data, and store location.

Sales data query

We may ask these questions related to sales …

How records are stored

• Each record is called a Document, which is BSON formatted.
• Documents are grouped into a Collection.
• Collections are grouped into a Database.

List all DB

> show dbs
admin   0.000GB
config  0.000GB
local …