Connecting to PostgreSQL

Installing PostgreSQL on Windows

Now that we know about PostgreSQL and why we need to use it, let's look at how we can install it in your system to use it practically.

1. Go to https://www.postgresql.org/download/ 

2. Select Windows.

3. Choose Interactive Installer by EnterpriseDB as Graphics Installer by BigSQL is outdated.

4. Choose the version you want and the Windows operating system environment, and click on download.

5. Wait for it to download.

6. Once downloaded, open the downloaded file .exe format.

7. Once you see the welcome screen, you can click "Next."

8. Set the location where you want to store the installation directory and click "Next."

9. A list of components appears on the next screen, make the choices and click on "Next."

10. Choose where you want to store the data files on your computer and click "Next."

11. Create a password and click "Next."

12. The port number is the default, so you can leave it as it is and click "Next."

13. The pre-installation is displayed on the screen; check it once before clicking next.

14. A new window will appear. Click "Next."

15. Stack builder is checked on default; uncheck it and click "Finish."

16. Open start and search for pgAdmin4. This will launch PostgreSQL.

17. On the home page of pgAdmin, you will have to search for PostgreSQL 10 on the left column and open it.

18. Enter the earlier set password and click on OK.

19. The installation is successful only when you can see the dashboard on the screen. 

Installing PostgreSQL in MacOS is the same as installing it in Windows.

Adding PostgreSQL to New Vaadin Applications

Now that you have installed PostgreSQL into your system, let's see how you can use it in your Vaadin applications.

1. Open Vaadin.
2. In Vaadin Start, go to the SETTINGS tab.
3. There you will have to select "Technology."
4. A new section will drop down where you can see the database on the 4th line. There you will have to select "PostgreSQL" in the dropdown.

Doing this creates a dependent file with the extension pom.xml, which is present in the project you have generated. All necessary configurations to connect to PostgreSQL are contained in the generated project.

<dependency>
  <groupId>org.postgresql</groupId>
  <artifactId>postgresql</artifactId>
</dependency>

This is what the dependency looks like in the pom.xml file by the generated project.

Since PostgreSQL uses Spring Datasource, you will see it on the configuration of PostgreSQL.  

Application.properties is generated once the project is generated; it looks like something given below.

# PostgreSQL configuration.
spring.datasource.url = jdbc:postgresql://localhost:5432/postgres
spring.datasource.username = postgres
spring.datasource.password = password
spring.jpa.hibernate.ddl-auto = update

The values given in this configuration are default. While installing PostgreSQL in your system, you would have set specific values for these configurations. Check if the values are the ones you have given during the installation.

When you begin the application, In your IDE's console, you should see something like this:

Database available at 'jdbc:postgresql://localhost:5432/postgres'

Adding PostgreSQL to an Existing Vaadin Project

You can add PostgreSQL to an existing Vaadin project by:

 ~ adding the pom.xml dependency file and application.properties configuration file to the project.

Frequently Asked Questions

What is a Relational Database Management System?

A relational database management system maintains a relationship between the data stored in the database. It also manages data and retrieves it whenever required. It also helps in querying the database.

Does Relational Database Management System provide an interface between the users and the application?

Yes, RDBMS provides an interface between the users and the application.

How is PostgreSQL different from MongoDB?

MongoDB is a document-based database, and it cant be compared to a relational database management system like PostgreSQL.

How is PostgreSQL different from MySQL?

PostgreSQL is the way to go if you have complex data and need an extensive database with many functions. MySQL is for smaller databases and for practice projects and mini-projects.

Conclusion

I am concluding this article by saying that I'm grateful you have read this entire article with utmost interest and dedication. I hope it met all that you were looking for and expect that you have installed PostgreSQL and are using it for your Vaadin projects.

You can also check out our materials related to this article, SQL vs. Non-SQL Databases, Normalisation, Fundamentals of Data Systems, PostgreSQL vs. MySQL, AWS Database, Skills for becoming a Data Scientist, Artificial Intelligence Engineer, System Design Strategies, Kaggle, and many more!