Connect a PostgreSQL database to a Spring Boot Application Tutorial

Summary

This tutorial video guides viewers on connecting a Spring Boot application with a PostgreSQL database. It covers creating a Maven project in Java 8, adding necessary dependencies, configuring properties for database connection, and using Spring Data JPA with Hibernate for ORM. The video demonstrates starting the application, creating a 'Person' entity, setting up a repository, and interacting with the database through a REST controller, showcasing CRUD operations.

Takeaways

• 😀 The video is a tutorial on connecting a Spring Boot application with a PostgreSQL database.
• 🔧 Viewers are directed to a previous video for instructions on installing PostgreSQL if needed.
• 🛠️ The tutorial uses Java 8 and Maven to create a Spring Boot project with web and JPA dependencies.
• 📚 Spring Data REST and Spring Boot Starter Data JPA are utilized for the project setup.
• 🔄 The video demonstrates the process of generating a Spring Boot project and importing it into IntelliJ.
• 🚫 The initial attempt to start the application fails due to missing data source URL details.
• 🌐 The data source URL and database credentials are retrieved from the PostgreSQL admin interface.
• 🔑 The tutorial explains how to configure the application properties for database connectivity.
• 🏗️ Hibernate is used internally by Spring Boot for JPA implementation, which requires setting the correct dialect.
• 📝 The video covers creating a 'Person' entity with ID and name fields, and setting up the corresponding JPA entity.
• 🔗 A repository interface is created extending JpaRepository to handle database operations for the 'Person' entity.
• 📡 A REST controller is set up to add and retrieve 'Person' data from the database using POST and GET mappings.

Q & A

What is the main topic of the video?

The video is about connecting a Spring Boot application with a PostgreSQL database.

What programming language is used in the video?

Java is the programming language used in the video.

What version of Java is mentioned in the video?

Java 8 is mentioned in the video.

What is the purpose of Spring Initializer in the video?

Spring Initializer is used to create a Maven project with specified dependencies for the Spring Boot application.

What dependencies are mentioned for the Spring Boot application?

Dependencies mentioned include web, Spring Data JPA, and PostgreSQL driver.

Why is the application failing to start initially?

The application fails to start initially because it cannot find the data source URL.

What property needs to be added to the application.properties file to fix the startup issue?

The 'spring.datasource.url' property needs to be added with the correct PostgreSQL database URL.

What does JPA stand for and what is its role in the video?

JPA stands for Java Persistence API, and it is used for managing relational data in the application.

What is the purpose of the 'spring.jpa.hibernate.ddl-auto' property in the application.properties file?

The 'spring.jpa.hibernate.ddl-auto' property is used to specify whether the database schema should be created or updated automatically when the application starts.

What is the entity created in the video?

A 'Person' entity is created in the video, with 'id' and 'name' as its fields.

What is the role of the 'PersonRepository' interface in the video?

The 'PersonRepository' interface is used to define the data access layer for the 'Person' entity, extending the functionality provided by Spring Data JPA.

How is data added to the PostgreSQL database in the video?

Data is added to the PostgreSQL database through a REST controller that handles POST requests to add new 'Person' entities.

How can the created 'Person' entity be retrieved from the database?

The created 'Person' entity can be retrieved by accessing the appropriate REST endpoint, such as 'localhost:8080/person/{id}', where '{id}' is the ID of the person.

Outlines

00:00

📚 Introduction and Project Setup

In this section, the speaker introduces the video topic, which is about connecting a Spring Boot application with a PostgreSQL database. They suggest referring to a previous video for PostgreSQL installation instructions and then proceed to demonstrate setting up a Maven project in Java using Spring Initializr. They select Java 8 and add dependencies such as web, REST repository, and JPA. The speaker emphasizes the use of JPA instead of JDBC template and mentions using Lombok for boilerplate code generation. After generating the project, they extract it and import it into IntelliJ IDEA.

05:00

🔧 Configuring Database Connection

The speaker attempts to start the Spring Boot application but encounters a failure due to a missing data source URL. They explain the need to configure the database reference for JPA by adding properties for the database URL, port, and name. The configuration specifies using a JDBC connection to PostgreSQL on localhost:5432 with a database named 'YT_demo'. The speaker demonstrates how to add these properties in the application.properties file and successfully restart the application, showing that it can now connect to the database.

10:06

🛠 Creating Entities and Repositories

The speaker guides through creating a model object for 'Person' with fields for ID and name. They annotate it as an entity and specify the table name. Next, they create a repository interface for the 'Person' entity, extending JPA repository and annotating it as a rest resource. They restart the application and demonstrate accessing the 'Person' data via a RESTful endpoint at localhost:8080/person. Initially, the data is empty, so the speaker shows how to add data using a POST request through a REST controller.

🚀 Testing and Finalizing

In the final section, the speaker demonstrates how to add a new person to the database using a POST request. They verify the addition by querying the database and retrieving the inserted record via the REST endpoint. The speaker emphasizes the capabilities of the REST repository for handling CRUD operations and concludes the video by summarizing the steps taken to connect the Spring Boot application with PostgreSQL and manage data using JPA. They thank the viewers and encourage them to watch the next video.

Keywords

💡Springboard

Springboard, in the context of this video, refers to the Spring Boot framework, which is a popular Java-based framework used for creating stand-alone, production-grade applications. It simplifies the bootstrapping and development of new Spring applications. The video's theme revolves around connecting a Spring Boot application with a PostgreSQL database, showcasing the integration process.

💡PostgreSQL

PostgreSQL, often referred to as Postgres, is a powerful, open-source object-relational database system with an emphasis on extensibility and standards compliance. In the video, the presenter is demonstrating how to connect a Spring Boot application to a PostgreSQL database, which is a key concept for setting up data persistence in modern applications.

💡Maven

Maven is a build automation tool used primarily for Java projects. It is designed to make the build process easier by providing a set of standard actions that can be performed on a project. In the script, Maven is used to create a new Spring Boot project with specified dependencies, which is fundamental to the video's tutorial on setting up the project environment.

💡JPA

JPA, or Java Persistence API, is a specification that describes the management of relational data in Java applications with object-oriented domain models. The video discusses using JPA for database operations within the Spring Boot application, which abstracts the database interactions and allows for a more streamlined development process.

💡Spring Initializer

Spring Initializer is a tool provided by the Spring Boot team to bootstrap a new Spring application with the necessary dependencies and configurations. The video script mentions using Spring Initializer to create a Maven project, which sets the foundation for the subsequent steps of connecting to a PostgreSQL database.

💡REST Repository

A REST Repository in Spring Boot is an interface that extends the JpaRepository interface, providing a set of methods to interact with the database through a RESTful API. The video script describes using a REST Repository to create, read, update, and delete operations on the 'Person' entity, demonstrating how to work with data in a Spring Boot application.

💡Lombok

Lombok is a Java library that automatically plugs into your editor and build tools, spicing up your Java code with annotations. It helps to reduce boilerplate code by automatically generating common code constructs such as getters, setters, constructors, and more. In the script, Lombok is mentioned as a tool for simplifying the code generation process in the Spring Boot application.

💡DataSource URL

The DataSource URL is a string that specifies the location and access details of a database. In the video, the presenter discusses providing the DataSource URL to connect the Spring Boot application to the PostgreSQL database, which is crucial for establishing the database connection.

💡Hibernate

Hibernate is an object-relational mapping (ORM) library for the Java language, providing a framework for mapping an object-oriented domain model to a traditional relational database. The video mentions that Spring Boot uses Hibernate under the hood when working with JPA, which facilitates the interaction between the application and the database.

💡Dialect

In the context of JPA and Hibernate, a dialect refers to a specific set of SQL constructs that are used to communicate with a particular type of database. The video script includes setting the PostgreSQL dialect to ensure that Hibernate generates SQL that is compatible with PostgreSQL, which is essential for the correct functioning of the database operations.

💡Entity

In JPA, an Entity represents a row in a database table. The video script describes creating a 'Person' entity, which corresponds to a 'person' table in the database. This entity includes fields such as 'id' and 'name', which map to the columns in the database table.

💡RestController

A RestController in Spring Boot is a class that handles HTTP requests and returns responses, typically used to create RESTful APIs. The video script includes creating a RestController to add and retrieve 'Person' entities, demonstrating how to expose the application's functionality over HTTP.

Highlights

Introduction to connecting a Spring Boot application with a PostgreSQL database.

Reference to a previous video on installing PostgreSQL.

Starting by creating a Maven project in Java using Spring Initializer.

Using Java 8 and dependencies for web development.

Choosing REST Repository and JPA for the project setup.

Using Spring Data JPA instead of JDBC template.

Utilizing Lombok for boilerplate code generation.

Generating the project with the specified dependencies.

Importing the generated project into IntelliJ.

Starting the application and encountering an error related to the data source URL.

Providing database connection details in the application properties.

Specifying the PostgreSQL JDBC URL and database name.

Restarting the application to establish a connection with the database.

Using Hibernate internally by Spring Boot for JPA implementation.

Configuring the PostgreSQL dialect for Hibernate.

Creating a new model object for a 'Person' entity.

Adding necessary fields to the 'Person' entity.

Creating a repository interface extending JpaRepository.

Restarting the application and accessing the '/person' endpoint.

Adding values to the database through a REST controller.

Querying the database to verify the added values.

Retrieving data from the database using the REST repository.

Conclusion and future plans for the next video.

Transcripts

hey guys welcome back

in this video we're going to see

how we can connect a springboard

application with postgres SQL database

right so if you have any doubt on how to

install the postgres SQL in your mission

you can refer to my previous video I'll

give you the link in the description and

also uh as a label okay so let's jump

into the video

let's start by going into spring

initializer I'm going to create a maven

project in Java

[Music]

that's what I'm going to use Java 8.

that dependencies I'm going to use web

so the normal dependencies what that

we'll use tools

I'm going to use rest

Repository

[Music]

what else you need uh I don't think I'm

going to get the main one is GPA that's

what we're going to use we are not going

to use jdbc template we are going to use

jspa

um I'll use Slumber for Generation the

boilerplate code generation

which driver okay I think that's all we

need let's click on generate so it will

generate the project for us

that we got we'll go to the folder

let me extract it

is

extracted

let me go to IntelliJ and import the

projector

foreign

[Music]

let's start the application now let's

see what happens

trying to start the application

[Music]

yeah it's failed uh it is searching for

the data source URL uh so that's where

it's failing so let's keep those details

because we have the postcode SQL refined

in our dependency so if you look at here

we have a post Craigslist SQL the jpa we

have to provide the data database

reference so the JPI is referring to the

data source URL that does not exist in

the resource let me go to the properties

and add few properties here which is

spring

the URL you can find it from our

admin you can just go to First cable

right click properties

and you can click on connection and you

can see it's on localhost

5432

right so let's take it from there

um

you're just going to see jdbc it's a

jdbc connection

and we are connecting it to post scratch

or screen skill

and the URL is going to be local

host

and five four three two that's the port

right and then we are going to use the

database which is here is YT demo that's

going to be very useful

right and we are we have the data source

so with this let's see let's let's start

the application so uh

let's restart the application again

[Music]

there you go the application is started

right it's able to connect to the

database and get all the details so I uh

JP is internally using hibernate to

connect the screen like here in

springboard so let's give some more

details like

um the dialect that it needs to use it

[Music]

but like the spring boot uses hibernate

for jpa implementation so that's why we

are providing the uh postgrades SQL

dialect

create so let's say if you want to

create anything create a table or

complete anything so we it will all work

in the way of postgres SQL

through JPM

so that's why we're giving this dialect

that's where it is and let's go and um

create the entities

so if you want to give more details

there are

like you can

provide I will need to show the details

or whatever it may be in the console you

can stop that and also you can update

the database

I mean like you can you can do a create

or update the database whenever the

server is restarted so all those stuff

you can do here so let me add that

property also

so far and let's go ahead and create a

new

model object

before and let's say let me create one

for

person

it's going to be a normal one right

create this

and I'll add it to a package called

Model so it should be

inside

temperature

as data

that way you don't need to give any

[Music]

Getters and Setters right and also this

is and this is going to be an entity for

us

jpa

and I'll also give the table name

and the table name is going to be

person

that's all it is and I'm going to create

a ID name

that's that's all I'm going to do now

create private

and

[Music]

long

ID

drive it

string name

so the two Fields I'm gonna create let

me go here and I just want to treat this

as an ID

there we go we created an object

entity we created an entity and we've

created an uh

created two uh members which is ID and

name this is going to be the columns one

is the ID which is the primary key for

this person let me go ahead and create

one more package which is Repository

foreign

let me add new

channel so it's going to be an interface

create an interface

it's going to be

Arsen repo

going to

extend this with jpa

I'm going to annotate this as

restroom

rest resource

and there you go that's all we need so

let me restart the application

[Music]

the start of the application let's go

ahead and hit this URL

localhost 8080 slash

person

I have this

to see what we have

here we have this URL

person

s

we see if you look at here the persons

is empty

so let's let's add some values to the

data database through our risk

controller let's create one risk

controller

you can add value for us

person raised person controller

[Music]

and we are going to use this as a

rest controller

will Define a

post mapping sorry

[Music]

[Music]

the name of course

we hit it from here

so by now it should have created uh

table here

very true

[Music]

because we

[Music]

start the server if the table does not

exist it will create

sell it

[Music]

foreign

[Music]

so let me go ahead here

and

head

add person

it's going to be post mapping and the

body is going to be

it's going to be

name

it's going to say and boom and

write this send it again

there you go it could add it

let me go to database and just query

this

[Music]

there you go we got the value updated

and if you want to get the value back

right so we already have the rest

repository configured so we just go here

and hit the URL just refresh the page so

you can see here there is a record in

this person

you can get through this person you in

this even through this URL let's give

slash zero

and you get there

get the complete object for that that's

why we are using the risk repository

here right so even like this way you can

do uh update delete you can create your

own methods and do it right

that's all uh

that's all we have for um

connecting springboard application with

a postgres SQL we'll see you in the next

video thanks for watching

[Music]