How to Connect to a Database from Spring Boot
- Add the database dependency. To connect your Spring Boot application to the database, you can add either of the...
- Configure JDBC Database driver. After all, you will be able to call the database through your repository calls if there...
- Database connection properties. We have configured our required dependencies. Overall, we...
Full Answer
How do I connect to a database using Spring Boot starter data-JPA?
While spring-boot-starter-data-jpa allows you to access databases through repositories using JPQL. The next step is to add a database driver matching the database that you want to connect. For example, the below snippets will let you add JDBC drivers for MySQL, Oracle, and PostgreSQL.
How to use MySQL JDBC driver in Spring Boot?
To use MySQL JDBC driver, declare the following dependency in the Maven pom.xml file of your Spring Boot project: <dependency> <groupId>mysql</groupId> <artifactId>mysql-connector-java</artifactId> <scope>runtime</scope> </dependency> You don’t need to specify the version as Spring Boot uses the default version specified in the parent POM. 2.
How to create a DataSource in Spring Boot?
We need not write any extra code to create a DataSource in Spring Boot. Just adding the dependencies and doing the configuration details is enough to create a DataSource and connect the Database. In this chapter, we are going to use Spring Boot JDBC driver connection to connect the database.
How do I use jdbctemplate in Spring Boot?
JDBCTemplate To access the Relational Database by using JdbcTemplate in Spring Boot application, we need to add the Spring Boot Starter JDBC dependency in our build configuration file. Then, if you @Autowired the JdbcTemplate class, Spring Boot automatically connects the Database and sets the Datasource for the JdbcTemplate object.
How does spring boot project connect to database?
To access the Relational Database by using JdbcTemplate in Spring Boot application, we need to add the Spring Boot Starter JDBC dependency in our build configuration file. Then, if you @Autowired the JdbcTemplate class, Spring Boot automatically connects the Database and sets the Datasource for the JdbcTemplate object.
How does spring JPA connect to database?
How To Connecting Spring Boot With MySQLStep 1 — Create Project.Step 2— Create a DB.Step 3— Create an Entity/ Model / Table that will be placed in the database.Step 4— Add this to application. properties. server.port=YOUR_PORT. spring.jpa.generate-ddl=true. spring.jpa.show-sql=true.
How do I know if spring boot is connected to database?
The easiest way to test the database connection from Spring boot is to start the application and by checking to debug logs.
What is the spring boot default database connection?
Spring Boot uses HikariCP as the default connection pool, due to its remarkable performance and enterprise-ready features.
How does spring boot JPA connect to multiple databases?
Follow the below steps:Add an additional datasource configuration to your application. ... Set the SQL Dialect to “default” in your application. ... Create a Java Package for each datasource with two nested Packages.Create a Configuration Class for the First database.Create a Configuration Class for the Second database.More items...•
How does spring boot JPA work?
Spring Boot JPA is a Java specification for managing relational data in Java applications. It allows us to access and persist data between Java object/ class and relational database. JPA follows Object-Relation Mapping (ORM). It is a set of interfaces.
Which database is best for spring boot?
MongoDB is an open-source NoSQL document database that uses a JSON-like schema instead of traditional table-based relational data. Spring Boot offers several conveniences for working with MongoDB, including the spring-boot-starter-data-mongodb 'Starter'.
How do I connect two databases in spring boot?
To connect multiple databases, each database should be configured in its own spring boot configuration file. Multiple data sources should be configured for multiple databases. For spring data classes and spring data JPA repositories, two separate java packages need be created.
What is JPA repository in spring boot?
JPA Repository is mainly used for managing the data in a Spring Boot Application. We all know that Spring is considered to be a very famous framework of Java. We mainly use this Spring Boot to create the Spring-based stand-alone and production-based applications with a very minimal amount of effort.
How does JDBC connection pool work?
A JDBC connection pool is a group of reusable connections for a particular database. Because creating each new physical connection is time consuming, the server maintains a pool of available connections to increase performance. When an application requests a connection, it obtains one from the pool.
What is in memory database in spring boot?
The in-memory database is an embedded database. The in-memory databases are volatile, by default, and all stored data loss when we restart the application. The widely used in-memory databases are H2, HSQLDB (HyperSQL Database), and Apache Derby. It creates the configuration automatically.
Which configuration in spring data JPA provides database connection details to the application?
Configuring Spring Data JPA We can configure Spring Data JPA by following these steps: Enable Spring Data JPA by annotating the PersistenceContext class with the @EnableJpaRepositories annotation. Configure the base packages that are scanned when Spring Data JPA creates implementations for our repository interfaces.
How are spring data repositories implemented at runtime?
In the repository interfaces, we can add the methods like findByCustomerNameAndPhone() (assuming customerName and phone are fields in the domain object). Then, Spring provides the implementation by implementing the above repository interface methods at runtime (during the application run).
How do I connect two spring boot databases?
To connect multiple databases, each database should be configured in its own spring boot configuration file. Multiple data sources should be configured for multiple databases. For spring data classes and spring data JPA repositories, two separate java packages need be created.
Which method can be used to store records in a database in JPA?
Instantiating a record in a CriteriaQuery You can use the construct method of JPA's CriteriaBuilder to define a constructor call in your CriteriaQuery. The first method parameter is a reference to the class Hibernate shall instantiate, and all other parameters will be used as constructor parameters.
What does Spring Boot do when you @Autowired the JDBCTemplate class?
Then, if you @Autowired the JdbcTemplate class, Spring Boot automatically connects the Database and sets the Datasource for the JdbcTemplate object.
What is @repository annotation?
The @Repository annotation should be added into the class file. The @Repository annotation is used to create database repository for your Spring Boot application.
Can Maven add dependencies?
Maven users can add the following dependencies in the pom.xml file.
Can you keep n datasources in Spring Boot?
We can keep ‘n’ number Datasources in a single Spring Boot application. The example given here shows how to create more than 1 data source in Spring Boot application. Now, add the two data source configuration details in the application properties file.
Is Spring Boot good for a database?
Spring Boot provides a very good support to create a DataSource for Database. We need not write any extra code to create a DataSource in Spring Boot. Just adding the dependencies and doing the configuration details is enough to create a DataSource and connect the Database.
Updating the Spring Boot Project Step By Step
Let’s look at the 5 steps involved in connecting a Spring Boot application to a database.
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What is Spring JDBC?
Spring JDBC provides a simple API on top of JDBC ( JdbcTemplate ), which you can use in simple cases, e.g. executing plain SQL statements. You need to declare the following dependency:
What APIs are used in Spring JDBC?
In case of Spring JDBC, use JdbcTemplate APIs for executing SQL statements against the database
What is Spring Data JPA?
Spring Data JPA provides more advanced API that greatly simplifies database programming based on Java Persistence API (JPA) specification with Hibernate as the implementation framework . You need to declare dependency for Spring Data JPA as follows:
How to make a connection to MySQL?
Basically, in order to make a connection to a MySQL server, you need to do the following steps: Declare a dependency for MySQL JDBC driver, which enables Java application to communicate with MySQL server. Declare a dependency for Spring JDBC or Spring Data JPA. Specify data source properties for the database connection information.
Do you need to specify Spring Boot version?
You don’t need to specify the version as Spring Boot uses the default version specified in the parent POM.
What is Spring Data JPA?
Spring Data JPA is a method to implement JPA repositories to add the data access layer in applications easily. CRUD stands for create, retrieve, update, delete which are the possible operations which can be performed in a database. In this article, we will see an example of how to access data from a database ( MySQL for this article) in a spring boot application using spring data JPA.
What is a database?
A database is a collection of inter-related data which helps in efficient retrieval, insertion and deletion of data from database and organizes the data in the form of tables, views, schemas, reports etc.
Add The Database Dependency
- To connect your Spring Boot applicationto the database, you can add either of the following dependencies and it will connect to the database. OR if you are a gradle fan like me, you can use this If you use JDBC dependency, then in your code, you will have to use JDBCTemplate to make database calls. This is a nice feature of Spring Boot. Nevertheles...
Configure JDBC Database Driver
- After all, you will be able to call the database through your repository calls if there is a real connection between your app and the database. For this reason, you will need a JDBC driver appropriate to your database. It can be PostgreSQL, MySQL, Microsoft SQL Server, or NoSQL database(like MongoDB OR Cassandra) driver. Add the following dependency if you are using P…
Database Connection Properties
- We have configured our required dependencies. Overall, we need to connect our spring boot application to the database now. We will set up the database properties for the same. These properties include database URL, username, and password. Most of these properties start with spring.datasource.*. Depending on what database you are using, the values for the properties wi…
Demo – Connect Spring Boot Application to Database
- To demonstrate this connection, I have created a simple application called databasedemo. I added the properties as shown above. Obviously, I added some debug logging as wellfor Hikari. The main class looks like the below: Now, if I start my application, I will see the log that shows our spring boot application connects to the database. Spring Boot offers a DataSource object that y…
Conclusion
- In this post, I showed how one can connect a spring boot application to the database. Spring Boot has made this easier by taking away a lot of boilerplate code. This allows developers to focus on business logic and not worry about database-level coding.