In this blog, I will explain how to use many-to-many mapping in Spring boot Application What you need? JAVA MySql Eclipse IDE ( whatever you like IDE, I'm using Eclipse for this example) Maven ( you can use the Gradle as well) Initial Plan spring boot application will be created using spring initializer web tool and imported as a maven project to the eclipse ide. Scenarios will be post and tags. one post have more than one tags and one tags have more than one posts. Two model classes will be created for Post and Tags. Finally, the command line runner interface will be used to run the application. Below diagram is the database model diagram which we going to install using the spring boot application. Let's Start to Code. You need to configure the application.properties file for database connections. add the following content to the src/main/resources/application.properties spring.datasource.url=jdbc:mysql://localhost:3306/learning spring.dataso