Spring Boot + PostgreSQL Custom Schema Demo

This project demonstrates three approaches to work with PostgreSQL schemas in Spring Boot:

1. Default schema for all entities via hibernate.default_schema
2. Per-entity schema using @Table(schema = "...")
3. Database search path using JDBC param currentSchema=my_schema

Tech:

• Java 21
• Spring Boot 3.3.x
• Spring Data JPA
• PostgreSQL 16
• Gradle (Groovy)
• Docker & Docker Compose

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Run with Docker Compose (recommended)

Requires Docker installed.

docker compose up --build

This will:

• Start Postgres on port 5432
• Build & run the Spring Boot app on port 8080

Once it's up, try these endpoints:

• POST http://localhost:8080/users/default/{name}
  Inserts into my_schema.users_default (default schema)

• POST http://localhost:8080/users/custom/{email}
  Inserts into other_schema.users_custom (entity-level schema)

• POST http://localhost:8080/users/mixed/{phone}
  Inserts into my_schema.users_mixed (resolved via currentSchema / search_path)

• GET http://localhost:8080/users/all
  Returns counts for all three tables

Stop all containers:

docker compose down

Data persists in the named Docker volume pgdata (remove via docker volume rm pgdata).

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Local run (optional)

If you want to run locally (without Docker), adjust spring.datasource.* in src/main/resources/application.yml to point to your local PostgreSQL, then:

./gradlew bootRun

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How it works

• schema.sql creates two schemas: my_schema and other_schema.
• application.yml sets:
  • hibernate.default_schema=my_schema (Approach A)
  • JDBC URL includes ?currentSchema=my_schema so search path prefers my_schema (Approach C)
• @Table(schema="other_schema") on UserCustom shows Approach B for one entity.

You can mix-and-match these depending on your needs.