In this tutorial, you'll learn how to install PostgreSQL 14.7 on your Ubuntu system. The process is straightforward and consists of the following steps:

1. Update your system packages
2. Install PostgreSQL
3. Set up the superuser
4. Download the Northwind PostgreSQL SQL file
5. Create a new Database
6. Import the Northwind SQL file
7. Verify the Northwind database installation
8. Connect to the Database Using Jupyter Notebook

• Click here for installation instructions on Windows 10
• Click here for installation instructions on MacOS

Prerequisites

To follow this tutorial, you should be running Ubuntu 20.04 LTS or later.

Step 1: Update System Packages

First, you need to update the system packages. Open the Terminal app ("Ctrl + Alt + T") and enter the following command:

sudo apt update && sudo apt upgrade -y

Enter your admin password when prompted. This command will update the package lists for upgrades for packages that need upgrading, as well as new packages that have just come to the repositories, and then upgrade the currently installed packages. The -y option will automatically answer 'yes' to all prompts, making the process non-interactive.

Note: sudo is a prefix that gives you superuser permissions for a command, which is often necessary when making system-wide changes like installing or upgrading software. Be careful when using sudo, as it provides complete control over your system, including the ability to break it if misused.

Step 2: Install PostgreSQL

With the system packages updated, you're ready to install PostgreSQL.

To install the PostgreSQL package, use the apt package manager:

sudo apt install postgresql-14

You may be prompted to confirm the amount of space the installation requires on your local system. After the installation is complete, check the status of the PostgreSQL service:

systemctl status postgresql

When you run this command, it will display information such as whether the service is active or inactive, when it was started, the process ID, and recent log entries. You'll know that it has been installed successfully if you see a line similar to Loaded: loaded (/lib/systemd/system/postgresql.service; enabled; vendor preset: enabled) indicating system has successfully read the PostgreSQL service file.

After you run systemctl status postgresql, you should find yourself back at the command prompt. If not, and you're stuck in a view of log files, you might be in a "less" or "more" program that lets you scroll through the logs. You can typically exit this view and return to the command prompt by pressing q. If that doesn't work, then "Ctrl + C" will send an interrupt signal to the current process and return you to the command line.

Step 3: Setting up the postgres user

PostgreSQL automatically creates a user (also known as a "role") named postgres. To ensure you'll be able to use PostgreSQL without any issues, let’s create a password for this user that has superuser privileges. You can set a password for this user with this command:

sudo -u postgres psql -c "ALTER USER postgres PASSWORD 'your_password';"

Replace your_password with a new password and make sure it is wrapped in single quotes. Please note, this is not your local user account's password. This password will be used to connect to your PostgreSQL database with superuser privileges, so make sure it's strong and secure. This command will run the psql command as the postgres user, and pass it a SQL command to change the postgres user's password to your_password.

In PostgreSQL, the terms "USER" and "ROLE" are essentially interchangeable. The ALTER USER command is actually an alias for ALTER ROLE, which is why you see ALTER ROLE as the confirmation message.

So when you see ALTER ROLE, it just means that the password change was successful and the postgres role (or user, in everyday terms) has a new password. You're now able to use this new password to connect to PostgreSQL as the postgres user.

Step 4: Download the Northwind PostgreSQL SQL file

First, you need to download a version of the Northwind database that's compatible with PostgreSQL. You can find an adapted version on GitHub. To download the SQL file, follow these two steps:

1. From the Terminal, create a new directory for the Northwind database and navigate to it:

   mkdir northwind && cd northwind

2. Download the Northwind PostgreSQL SQL file using wget:

   wget https://raw.githubusercontent.com/pthom/northwind_psql/master/northwind.sql

   This will download the northwind.sql file to the northwind directory you created above.

Step 5: Create a new PostgreSQL database

Before importing the Northwind SQL file, you must create a new PostgreSQL database. Follow these three steps:

1. Connect to the PostgreSQL server as the postgres user:

   sudo -u postgres psql

   This command is telling the system to execute the psql command as the postgres user. psql is the interactive terminal for PostgreSQL, and when it starts, it changes the command prompt to let you know that you're interacting with the PostgreSQL command-line and not the system command-line.

   Once you've run sudo -u postgres psql, your terminal prompt will change to something similar to postgres=# to indicate you're connected to the postgres database.

2. Create a new database called northwind:

   postgres=# CREATE DATABASE northwind;

   You'll see "CREATE DATABASE" is returned if the command is successful.

3. Exit the psql command-line interface:

   postgres=# \q

Step 6: Import the Northwind SQL file

With the northwind database created, you can import the Northwind SQL file using psql. Follow these steps:

• In your Terminal, ensure you're in the northwind directory where you downloaded the northwind.sql file.

• Run the following command to import the Northwind SQL file into the northwind database:

  sudo -u postgres psql -d northwind -f northwind.sql

  This command connects to the PostgreSQL server as the postgres user, selects the northwind database, and executes the SQL commands in the northwind.sql file.

Step 7: Verify the Northwind database installation

To verify that the Northwind database has been installed correctly, follow these four steps:

1. Connect to the northwind database using psql:

   sudo -u postgres psql -d northwind

2. List the tables in the Northwind database:

   northwind=# \dt

   You should see a list of Northwind tables: categories, customers, employees, orders, and more.

3. Run a sample query to ensure the data has been imported correctly. For example, you can query the customers table:

   northwind=# SELECT * FROM customers LIMIT 5;

   This should return the first five rows from the customers table. Similar to above when you used systemctl status postgresql, you might be in a "less" or "more" program that lets you scroll through the results of the query. Press q to return to the psql command-line interface.

4. Exit the psql command-line interface:

   northwind=# \q

Step 8: Connect to the Database Using Jupyter Notebook

As we wrap up our installation, we will now introduce Jupyter Notebook as one of the tools available for executing SQL queries and analyzing the Northwind database. Jupyter Notebook offers a convenient and interactive platform that simplifies the visualization and sharing of query results, but it's important to note that it is an optional step. You can also access Postgres through other means. However, we highly recommend using Jupyter Notebook for its numerous benefits and enhanced user experience.

To set up the necessary tools and establish a connection to the Northwind database, here is an overview of what each step will do:

• !pip install ipython-sql: This command installs the ipython-sql package. This package enables you to write SQL queries directly in your Jupyter Notebook, making it easier to execute and visualize the results of your queries within the notebook environment.
• %load_ext sql: This magic command loads the sql extension for IPython. By loading this extension, you can use the SQL magic commands, such as %sql and %%sql, to run SQL queries directly in the Jupyter Notebook cells.

• %sql postgresql://postgres@localhost:5432/northwind: This command establishes a connection to the Northwind database using the PostgreSQL database system. The connection string has the following format:

  postgresql://username@hostname:port/database_name

  • In this case, username is postgres, hostname is localhost, port is 5432, and database_name is northwind. The %sql magic command allows you to run a single-line SQL query in the Jupyter Notebook.

1. Copy the following text into a code cell in the Jupyter Notebook:

   !pip install ipython-sql
   %load_ext sql
   %sql postgresql://postgres@localhost:5432/northwind

2. Run the cell by either:

   • Clicking the "Run" button on the menu bar.
   • Using the keyboard shortcut: Shift + Enter or Ctrl + Enter.

3. Upon successful connection, you should see an output similar to the following:

   'Connected: postgres@northwind'

   This output confirms that you are now connected to the Northwind database, and you can proceed with the guided project in your Jupyter Notebook environment.

Once you execute these commands, you'll be connected to the Northwind database, and you can start writing SQL queries in your Jupyter Notebook using the %sql or %%sql magic commands.

Next Steps

Based on what you've accomplished, here are some potential next steps to continue your learning journey:

1. Deepen Your SQL Knowledge:
   • Try formulating more complex queries on the Northwind database to improve your SQL skills. These could include joins, subqueries, and aggregations.
   • Understand the design of the Northwind database: inspect the tables, their relationships, and how data is structured.
2. Experiment with Database Management:
   • Learn how to backup and restore databases in PostgreSQL. Try creating a backup of your Northwind database.
   • Explore different ways to optimize your PostgreSQL database performance like indexing and query optimization.
3. Integration with Python:
   • Learn how to use psycopg2, a popular PostgreSQL adapter for Python, to interact with your database programmatically.
   • Experiment with ORM (Object-Relational Mapping) libraries like SQLAlchemy to manage your database using Python.

In this tutorial, you'll learn how to install PostgreSQL 14.7 on Windows 10.

The process is straightforward and consists of the following steps:

1. Install PostgreSQL
2. Configure Environment Variables
3. Verify the Installation
4. Download the Northwind PostgreSQL SQL file
5. Create a New PostgreSQL Database
6. Import the Northwind SQL file
7. Verify the Northwind database installation
8. Connect to the Database Using Jupyter Notebook

• Click here for installation instructions on Ubuntu
• Click here for installation instructions on MacOS

Prerequisites

• A computer running Windows 10
• Internet connection

1. Download the official PostgreSQL 14.7 at https://get.enterprisedb.com/postgresql/postgresql-14.7-2-windows-x64.exe
2. Save the installer executable to your computer and run the installer.

Note: We recommend version 14.7 because it is commonly used. There are newer versions available, but their features vary substantially!

Step 1: Install PostgreSQL

We're about to initiate a vital part of this project - installing and configuring PostgreSQL.

Throughout this process, you'll define critical settings like the installation directory, components, data directory, and the initial 'postgres' user password. This password grants administrative access to your PostgreSQL system. Additionally, you'll choose the default port for connections and the database cluster locale.

Each choice affects your system's operation, file storage, available tools, and security. We're here to guide you through each decision to ensure optimal system functioning.

1. In the PostgreSQL Setup Wizard, click Next to begin the installation process.

   

2. Accept the default installation directory or choose a different directory by clicking Browse. Click Next to continue.

   

3. Choose the components you want to install (e.g., PostgreSQL Server, pgAdmin 4 (optional), Stack Builder (optional), Command Line Tools), and click Next.

   

4. Select the data directory for storing your databases and click Next.

   

5. Set a password for the PostgreSQL “postgres” user and click Next.

   

   • There will be some points where you're asked to enter a password in the command prompt. It's important to note that for security reasons, as you type your password, no characters will appear on the screen. This standard security feature is designed to prevent anyone from looking over your shoulder and seeing your password. So, when you're prompted for your password, don't be alarmed if you don't see any response on the screen as you type. Enter your password and press 'Enter'. Most systems will allow you to re-enter the password if you make a mistake.

   • Remember, it's crucial to remember the password you set during the installation, as you'll need it to connect to your PostgreSQL databases in the future.

6. Choose the default port number (5432) or specify a different port, then click Next.

   

7. Select the locale to be used by the new database cluster and click Next.

   

8. Review the installation settings and click Next to start the installation process. The installation may take a few minutes.

   

   

9. Once the installation is complete, click Finish to close the Setup Wizard.

Step 2: Configure Environment Variables

Next, we're going to configure environment variables on your Windows system. Why are we doing this? Well, environment variables are a powerful feature of operating systems that allow us to specify values - like directory locations - that can be used by multiple applications. In our case, we need to ensure that our system can locate the PostgreSQL executable files stored in the "bin" folder of the PostgreSQL directory.

By adding the PostgreSQL "bin" folder path to the system's PATH environment variable, we're telling our operating system where to find these executables. This means you'll be able to run PostgreSQL commands directly from the command line, no matter what directory you're in, because the system will know where to find the necessary files. This makes working with PostgreSQL more convenient and opens up the possibility of running scripts that interact with PostgreSQL.

Now, let's get started with the steps to configure your environment variables on Windows!

1. On the Windows taskbar, right-click the Windows icon and select System.

2. Click on Advanced system settings in the left pane.

3. In the System Properties dialog, click on the Environment Variables button.

   

4. Under the System Variables section, scroll down and find the Path variable. Click on it to select it, then click the Edit button.

5. In the Edit environment variable dialog, click the New button and add the path to the PostgreSQL bin folder, typically C:\Program Files\PostgreSQL\14\bin.

   

6. Click OK to close the "Edit environment variable" dialog, then click OK again to close the "Environment Variables" dialog, and finally click OK to close the "System Properties" dialog.

Step 3: Verify the Installation

After going through the installation and configuration process, it's essential to verify that PostgreSQL is correctly installed and accessible. This gives us the assurance that the software is properly set up and ready to use, which can save us from troubleshooting issues later when we start interacting with databases.

If something went wrong during installation, this verification process will help you spot the problem early before creating or managing databases.

Now, let's go through the steps to verify your PostgreSQL installation.

1. Open the Command Prompt by pressing Win + R, typing cmd, and pressing Enter.
2. Type psql --version and press Enter. You should see the PostgreSQL version number you installed if the installation was successful.
3. To connect to the PostgreSQL server, type psql -U postgres and press Enter.
4. When prompted, enter the password you set for the postgres user during installation. You should now see the postgres=# prompt, indicating you are connected to the PostgreSQL server.

Step 4: Download the Northwind PostgreSQL SQL File

Now, we're going to introduce you to the Northwind database and help you download it. The Northwind database is a sample database originally provided by Microsoft for its Access Database Management System. It's based on a fictitious company named "Northwind Traders," and it contains data on their customers, orders, products, suppliers, and other aspects of the business. In our case, we'll be working with a version of Northwind that has been adapted for PostgreSQL.

The following steps will guide you on how to download this PostgreSQL-compatible version of the Northwind database from GitHub to your local machine. Let's get started:

First, you need to download a version of the Northwind database that's compatible with PostgreSQL. You can find an adapted version on GitHub. To download the SQL file, follow these steps:

1. Open Command Prompt or PowerShell.

2. Create a new directory for the Northwind database and navigate to it:

   mkdir northwind
   cd northwind

3. Download the Northwind PostgreSQL SQL file using curl:

   curl -O https://raw.githubusercontent.com/pthom/northwind_psql/master/northwind.sql

   This will download the northwind.sql file to the northwind directory you created.

Step 5: Create a New PostgreSQL Database

Now that we've downloaded the Northwind SQL file, it's time to prepare our PostgreSQL server to host this data. The next steps will guide you in creating a new database on your PostgreSQL server, a crucial prerequisite before importing the Northwind SQL file.

Creating a dedicated database for the Northwind data is good practice as it isolates these data from other databases in your PostgreSQL server, facilitating better organization and management of your data. These steps involve connecting to the PostgreSQL server as the postgres user, creating the northwind database, and then exiting the PostgreSQL command-line interface.

Let's proceed with creating your new database:

1. Connect to the PostgreSQL server as the postgres user:

   psql -U postgres

2. Create a new database called northwind:

   postgres=# CREATE DATABASE northwind;

3. Exit the psql command-line interface:

   postgres=# \q

Step 6: Import the Northwind SQL File

We're now ready to import the Northwind SQL file into our newly created northwind database. This step is crucial as it populates our database with the data from the Northwind SQL file, which we will use for our PostgreSQL learning journey.

These instructions guide you through the process of ensuring you're in the correct directory in your Terminal and executing the command to import the SQL file. This command will connect to the PostgreSQL server, target the northwind database, and run the SQL commands contained in the northwind.sql file.

Let's move ahead and breathe life into our northwind database with the data it needs!

With the northwind database created, you can import the Northwind SQL file using the psql command. Follow these steps:

1. In your Terminal, ensure you're in the northwind directory where you downloaded the northwind.sql file.

2. Run the following command to import the Northwind SQL file into the northwind database:

   psql -U postgres -d northwind -f northwind.sql

   This command connects to the PostgreSQL server as the postgres user, selects the northwind database, and executes the SQL commands in the northwind.sql file.

Step 7: Verify the Northwind Database Installation

You've successfully created your northwind database and imported the Northwind SQL file. Next, we must ensure everything was installed correctly, and our database is ready for use.

These upcoming steps will guide you on connecting to your northwind database, listing its tables, running a sample query, and finally, exiting the command-line interface. Checking the tables and running a sample query will give you a sneak peek into the data you now have and verify that the data was imported correctly. This means we can ensure everything is in order before diving into more complex operations and analyses.

To verify that the Northwind database has been installed correctly, follow these steps:

1. Connect to the northwind database using psql:

   psql -U postgres -d northwind

2. List the tables in the Northwind database:

   postgres=# \dt

   You should see a list of Northwind tables: categories, customers, employees, orders, and more.

3. Run a sample query to ensure the data has been imported correctly. For example, you can query the customers table:

   postgres=# SELECT * FROM customers LIMIT 5;

   This should return the first five rows from the customers table.

4. Exit the psql command-line interface:

   postgres=# \q

Congratulations! You've successfully installed the Northwind database in PostgreSQL using an SQL file and psql.

Step 8: Connect to the Database Using Jupyter Notebook

As we wrap up our installation, we will now introduce Jupyter Notebook as one of the tools available for executing SQL queries and analyzing the Northwind database. Jupyter Notebook offers a convenient and interactive platform that simplifies the visualization and sharing of query results, but it's important to note that it is an optional step. You can also access Postgres through other means. However, we highly recommend using Jupyter Notebook for its numerous benefits and enhanced user experience.

To set up the necessary tools and establish a connection to the Northwind database, here is an overview of what each step will do:

1. !pip install ipython-sql: This command installs the ipython-sql package. This package enables you to write SQL queries directly in your Jupyter Notebook, making it easier to execute and visualize the results of your queries within the notebook environment.

2. %sql postgresql://postgres@localhost:5432/northwind: This command establishes a connection to the Northwind database using the PostgreSQL database system. The connection string has the following format:

   postgresql://username@hostname:port/database_name

   In this case, username is postgres, hostname is localhost, port is 5432, and database_name is northwind. The %sql magic command allows you to run a single-line SQL query in the Jupyter Notebook.

3. Copy the following text into a code cell in the Jupyter Notebook:

   !pip install ipython-sql
   %load_ext sql
   %sql postgresql://postgres@localhost:5432/northwind 

   On Windows you may need to try the following command because you need to provide the password you set for the “postgres” user during installation:

   %sql postgresql://postgres:{password}@localhost:5432/northwind

   Bear in mind that it's considered best practice not to include sensitive information like passwords directly in files that could be shared or accidentally exposed. Instead, you can store your password securely using environment variables or a password management system (we'll link to some resources at the end of this guide if you are interested in doing this).

4. Run the cell by either:

   • Clicking the "Run" button on the menu bar.
   • Using the keyboard shortcut: Shift + Enter or Ctrl + Enter.

5. Upon successful connection, you should see an output similar to the following:

   'Connected: postgres@northwind'

   This output confirms that you are now connected to the Northwind database, and you can proceed with the guided project in your Jupyter Notebook environment.

Once you execute these commands, you'll be connected to the Northwind database, and you can start writing SQL queries in your Jupyter Notebook using the %sql or %%sql magic commands.

Next Steps

Based on what you've accomplished, here are some potential next steps to continue your learning journey:

1. Deepen Your SQL Knowledge:
   • Try formulating more complex queries on the Northwind database to improve your SQL skills. These could include joins, subqueries, and aggregations.
   • Understand the design of the Northwind database: inspect the tables, their relationships, and how data is structured.
2. Experiment with Database Management:
   • Learn how to backup and restore databases in PostgreSQL. Try creating a backup of your Northwind database.
   • Explore different ways to optimize your PostgreSQL database performance like indexing and query optimization.
3. Integration with Python:
   • Learn how to use psycopg2, a popular PostgreSQL adapter for Python, to interact with your database programmatically.
   • Experiment with ORM (Object-Relational Mapping) libraries like SQLAlchemy to manage your database using Python.
4. Security and Best Practices:
   • Learn about database security principles and apply them to your PostgreSQL setup.
   • Understand best practices for storing sensitive information, like using .env files for environment variables.
   • For more guidance on securely storing passwords, you might find the following resources helpful:
     • Using Environment Variables in Python
     • Python Secret Module

In this tutorial, you'll learn how to install PostgreSQL 14.7 on your MacBook using Homebrew, a popular package manager for macOS.
The process is straightforward and consists of the following steps:

1. Install Homebrew
2. Install PostgreSQL
3. Download the Northwind PostgreSQL SQL file
4. Create a New PostgreSQL Database
5. Import the Northwind SQL file
6. Verify the Northwind database installation
7. Connecting to the Database Using Jupyter Notebook

• Click here for installation instructions on Windows 10
• Click here for installation instructions on Ubuntu

Prerequisites

You'll need a MacBook or iMac running macOS 10.13 or later to follow this tutorial.

Install Xcode Command Line Tools
First, you need to install the Xcode Command Line Tools, which provide essential tools for building software on your Mac.

1. Open the Terminal app (you can find it in Applications > Utilities) and enter the following command:

xcode-select --install

A pop-up window will appear, prompting you to install the Command Line Tools. Click on "Install" to proceed. Once the installation is complete, you can move on to the next step.

Step 1: Install Homebrew

With the Xcode Command Line Tools installed, you can now install Homebrew itself. Homebrew is a package manager for macOS that will make it easier for us to install PostgreSQL and manage other software packages.

After installing Homebrew, it's important to add it to your system's PATH. By doing this, we're telling the system where to find the Homebrew executables. This means you can run Homebrew commands directly from any location in your Terminal.

We will then verify the successful installation of Homebrew using the version check command. This crucial step confirms that Homebrew has been correctly installed and is accessible via your Terminal.

Now, let's get started with the installation of Homebrew and its addition to your system's PATH.

1. Copy and paste the following command into the Terminal app

The script will automatically download and install Homebrew on your Mac. You might be prompted to enter your admin password during the installation process. After the installation is complete, you will see a message saying, "Installation successful!"

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install.sh)"

2. Add Homebrew to Your PATH

Follow the steps below to complete the Homebrew installation:

(echo; echo 'eval "$(/opt/homebrew/bin/brew shellenv)"') >> /Users/user_name/.zprofile

This command appends the necessary line to your .zprofile file to load Homebrew into your PATH. Replace /Users/user_name with your actual user directory.

3. Running the command

Now, run the second command:

eval "$(/opt/homebrew/bin/brew shellenv)"

This command loads the Homebrew environment variables into your current Terminal session.

4. Verify the installation

To verify your Homebrew installation, run the following command:

brew --version

This should display the Homebrew version number, confirming that it's installed and available in your PATH.

Step 2: Install PostgreSQL

In this step, we will utilize Homebrew to set up PostgreSQL on your macOS system. The steps will guide you through updating Homebrew to guarantee that we're accessing the latest software packages. Next, we'll install PostgreSQL version 14 using a single Homebrew command, and start the PostgreSQL service, getting the database server up and running.

Finally, we'll secure our PostgreSQL installation by creating a new user (or "role") called postgres with superuser privileges. This user will serve as our primary means of interacting with our PostgreSQL server, granting us broad administrative capabilities. Now, let's dive into these steps:

1. Ensure Homebrew is Installed

Make sure you have Homebrew installed. If not, you can install it using the following command:

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/install.sh)"

2. Update Homebrew

Update Homebrew to ensure you have the latest package information

brew update

3. Install PostgreSQL 14

Install PostgreSQL 14 using Homebrew by entering the following command:

brew install postgresql@14

4. Start PostgreSQL Service

After the installation process is done, start the PostgreSQL service:

brew services start postgresql@14

You should see a message indicating that PostgreSQL has started successfully:

Successfully started postgresql@14

5. Verify PostgreSQL Installation
To ensure PostgreSQL is installed correctly, check the version:

psql --version

6. Create a PostgreSQL User

To ensure you will be able to use PostgreSQL without any issues, let’s create a new PostgreSQL user (also called a "role") named postgres with superuser privileges:

createuser -s postgres

7. Set a Password for the postgres User

For security purposes, set a password for the postgres user:

psql
\password postgres

8. Configure PostgreSQL Environment

Add PostgreSQL to your PATH by adding the following line to your shell profile (~/.zshrc or ~/.bash_profile):

export PATH="/usr/local/opt/postgresql@14/bin:$PATH"

Then, reload your profile:

source ~/.zshrc   # or source ~/.bash_profile

9. Troubleshooting Tips

If the PostgreSQL service does not start, check the logs for errors:

tail -f /usr/local/var/log/postgres.log

Ensure your system has enough resources and dependencies for PostgreSQL.

Step 3: Download the Northwind PostgreSQL SQL File

Now, we're going to introduce you to the Northwind database and help you download it. The Northwind database is a sample database originally provided by Microsoft for its Access Database Management System. It's based on a fictitious company named "Northwind Traders," and it contains data on their customers, orders, products, suppliers, and other aspects of the business. In our case, we'll be working with a version of Northwind that has been adapted for PostgreSQL.

The following steps will guide you on how to download this PostgreSQL-compatible version of the Northwind database from GitHub to your local machine. Let's get started:

First, you need to download a version of the Northwind database that's compatible with PostgreSQL. You can find an adapted version on GitHub. To download the SQL file, follow these steps:

1. Open your Terminal application.

2. Create a new directory for the Northwind database and navigate to it:

   mkdir northwind && cd northwind

3. Download the Northwind PostgreSQL SQL file using curl:

   curl -O https://raw.githubusercontent.com/pthom/northwind_psql/master/northwind.sql

   This will download the northwind.sql file to the northwind directory you created.

Step 4: Create a New PostgreSQL Database

Now that we've downloaded the Northwind SQL file, it's time to prepare our PostgreSQL server to host this data. The next steps will guide you in creating a new database on your PostgreSQL server, a crucial prerequisite before importing the Northwind SQL file.

Creating a dedicated database for the Northwind data is good practice as it isolates these data from other databases in your PostgreSQL server, facilitating better organization and management of your data. These steps involve connecting to the PostgreSQL server as the postgres user, creating the northwind database, and then exiting the PostgreSQL command-line interface.

Let's proceed with creating your new database:

1. Connect to the PostgreSQL server as the postgres user:

   psql -U postgres

2. Create a new database called northwind:

   postgres=# CREATE DATABASE northwind;

3. Exit the psql command-line interface:

   postgres=# \q

Step 5: Import the Northwind SQL File

We're now ready to import the Northwind SQL file into our newly created northwind database. This step is crucial as it populates our database with the data from the Northwind SQL file, which we will use for our PostgreSQL learning journey.

These instructions guide you through the process of ensuring you're in the correct directory in your Terminal and executing the command to import the SQL file. This command will connect to the PostgreSQL server, target the northwind database, and run the SQL commands contained in the northwind.sql file.

Let's move ahead and breathe life into our northwind database with the data it needs!

With the northwind database created, you can import the Northwind SQL file using psql. Follow these steps:

1. In your Terminal, ensure you're in the northwind directory where you downloaded the northwind.sql file.
2. Run the following command to import the Northwind SQL file into the northwind database:

   psql -U postgres -d northwind -f northwind.sql

   This command connects to the PostgreSQL server as the postgres user, selects the northwind database, and executes the SQL commands in the northwind.sql file.

Step 6: Verify the Northwind Database Installation

You've successfully created your northwind database and imported the Northwind SQL file. Next, we must ensure everything was installed correctly, and our database is ready for use.

These upcoming steps will guide you on connecting to your northwind database, listing its tables, running a sample query, and finally, exiting the command-line interface. Checking the tables and running a sample query will give you a sneak peek into the data you now have and verify that the data was imported correctly. This means we can ensure everything is in order before diving into more complex operations and analyses.

To verify that the Northwind database has been installed correctly, follow these steps:

1. Connect to the northwind database using psql:

   psql -U postgres -d northwind

2. List the tables in the Northwind database:

   postgres=# \dt

   You should see a list of Northwind tables: categories, customers, employees, orders, and more.

3. Run a sample query to ensure the data has been imported correctly. For example, you can query the customers table:

   postgres=# SELECT * FROM customers LIMIT 5;

   This should return the first five rows from the customers table.

4. Exit the psql command-line interface:

   postgres=# \q

Congratulations! You've successfully installed the Northwind database in PostgreSQL using an SQL file and psql.

Step 7: Connect to the Database Using Jupyter Notebook

As we wrap up our installation, we will now introduce Jupyter Notebook as one of the tools available for executing SQL queries and analyzing the Northwind database. Jupyter Notebook offers a convenient and interactive platform that simplifies the visualization and sharing of query results, but it's important to note that it is an optional step. You can also access Postgres through other means. However, we highly recommend using Jupyter Notebook for its numerous benefits and enhanced user experience.

To set up the necessary tools and establish a connection to the Northwind database, here is an overview of what each step will do:

1. !pip install ipython-sql: This command installs the ipython-sql package. This package enables you to write SQL queries directly in your Jupyter Notebook, making it easier to execute and visualize the results of your queries within the notebook environment.

2. %load_ext sql: This magic command loads the sql extension for IPython. By loading this extension, you can use the SQL magic commands, such as %sql and %%sql, to run SQL queries directly in the Jupyter Notebook cells.

3. %sql postgresql://postgres@localhost:5432/northwind: This command establishes a connection to the Northwind database using the PostgreSQL database system. The connection string has the following format:

   'postgresql://username@hostname:port/database_name'

   In this case, username is postgres, hostname is localhost, port is 5432, and database_name is northwind. The %sql magic command allows you to run a single-line SQL query in the Jupyter Notebook.

4. Copy the following text into a code cell in the Jupyter Notebook:

   !pip install ipython-sql
   %load_ext sql
   %sql postgresql://postgres@localhost:5432/northwind

5. Run the cell by either:

   • Clicking the "Run" button on the menu bar.
   • Using the keyboard shortcut: Shift + Enter or Ctrl + Enter.

6. Upon successful connection, you should see an output similar to the following:

   'Connected: postgres@northwind'

   This output confirms that you are now connected to the Northwind database, and you can proceed with the guided project in your Jupyter Notebook environment.

Once you execute these commands, you'll be connected to the Northwind database, and you can start writing SQL queries in your Jupyter Notebook using the %sql or %%sql magic commands.

Next Steps

Based on what you've accomplished, here are some potential next steps to continue your learning journey:

1. Deepen Your SQL Knowledge:
   • Try formulating more complex queries on the Northwind database to improve your SQL skills. These could include joins, subqueries, and aggregations.
   • Understand the design of the Northwind database: inspect the tables, their relationships, and how data is structured.
2. Experiment with Database Management:
   • Learn how to backup and restore databases in PostgreSQL. Try creating a backup of your Northwind database.
   • Explore different ways to optimize your PostgreSQL database performance like indexing and query optimization.
3. Integration with Python:
   • Learn how to use psycopg2, a popular PostgreSQL adapter for Python, to interact with your database programmatically.
   • Experiment with ORM (Object-Relational Mapping) libraries like SQLAlchemy to manage your database using Python.