🚀 Spring Boot: Database Initialization with Multiple SQL Files

This is a simple Spring Boot project that demonstrates how to initialize a database using multiple, organized SQL script files at startup.

Instead of relying on the default schema.sql and data.sql files, this project uses a custom DatabaseInitializationService to load scripts from specific directories (db/migration/schema/ and db/migration/data/). This allows for better organization of your database scripts.

🛠️ Technologies Used

• Java 21
• Spring Boot
• Spring Data JPA: For database interaction
• Spring Web: For creating REST endpoints
• MySQL: The relational database
• Lombok: To reduce boilerplate code

⚙️ How to Run This Project

1. Prerequisites

• You must have Java 21 (JDK) installed.
• You must have a MySQL Server running on your computer.

2. Configure the Database

1. Create the Database: Before running the application, you must create the database that Spring Boot will connect to. Run this command in your MySQL client (like MySQL Workbench or the command line):

   CREATE DATABASE example;

2. Edit application.properties: Open the src/main/resources/application.properties file. You must update the username and password to match your local MySQL credentials.

   spring.datasource.url=jdbc:mysql://localhost:3306/example
   spring.datasource.username=root
   spring.datasource.password=Aman  

3. Run the Application

The easiest way to run the project is from your IDE (like IntelliJ IDEA):

1. Find the SpringBootWithMultipleSqlImportFilesApplication.java file.
2. Right-click on it and select "Run".

The application will start on http://localhost:8080.

🧪 Testing the Endpoints

Once the application is running, the database will be automatically initialized with data from the SQL files. You can view the data by visiting these URLs in your web browser:

• Get All Users: http://localhost:8080/api/users

• Get All Products: http://localhost:8080/api/products

📁 Key Project Files

• service/DatabaseInitializationService.java This is the most important file. The @PostConstruct annotation tells Spring to run the initializeDatabase() method at startup, which executes all scripts in the schema and data folders.

• application.properties Note that spring.jpa.hibernate.ddl-auto=none is set. This is important! It tells Hibernate not to create tables, allowing our custom scripts to take full control.

• src/main/resources/db/migration/schema/ This directory holds all the CREATE TABLE scripts (schema1.sql, schema2.sql).

• src/main/resources/db/migration/data/ This directory holds all the INSERT INTO scripts (data1.sql, data2.sql).

👨‍💻 Author

• Aman Manwatkar