Data Access Module

Part I.

• Secondary Adapter to DB
• Mapper
• Explicit Repositories to DB

flowchart TB
   subgraph adapter
   end
   subgraph entity

   end
   subgraph exception

   end
   subgraph mapper
   end
   subgraph repository
   end

   repository --> adapter
   mapper --> adapter
   entity --> adapter
   exception --> adapter

Recommendations

Follow these steps

1. Create an entity class.
2. [Optional] Create an exception class.
3. Create a mapper class:
   1. Method From Entity to Domain Model.
   2. Method From Domain Model to Entity.
4. Create a Jpa Repository.
5. Create an adapter for jpa repository (Secondary Adapter).
   1. [Optional] Implement Domain OutPort(Repository).

Dependencies

<dependencies>
   <dependency>
      <groupId>com.blanksystem</groupId>
      <artifactId>blank-application-service</artifactId>
   </dependency>
   <!--lg5 dependencies-->
   <dependency>
      <groupId>com.lg5.spring</groupId>
      <artifactId>lg5-spring-data-jpa</artifactId>
   </dependency>
   <!-- if you need SAGA Pattern/Outbox Pattern, else remove dependencies -->
   <dependency>
      <groupId>com.lg5.spring.outbox</groupId>
      <artifactId>lg5-spring-outbox</artifactId>
   </dependency>
</dependencies>

💾 Migrations with liquibase

Recommendation: Use the following keywords to filename, for instance:
DDL: For schema or structural changes such as creating tables, modifying columns, adding indexes, or constraints.
DML: For data operations such as inserting, updating, or deleting records.
DATA: For large data imports, migrations, or initial data loads.
Patch: For small fixes or patches applied to correct data or structure issues. View: For database view creation or modifications.
Proc: For creating or altering stored procedures or functions in the database.

Example:

ddl-v.0.0.1.yaml
dml-v.0.0.2.yaml
ddl-v.0.0.3.yaml

Project Structure

src
 ├── java/
 │  └── com.blanksystem.blank.service.data
 │      ├── adapter/
 │      │  └── *.java
 │      ├── entity/
 │      │  └── *.java
 │      ├── exception/
 │      │  └── *.java
 │      ├── mapper/
 │      │  └── *.java
 │      └── repository/
 │         └── *JPARepository.java
 └── resources/
    └── db/
       └── changelog/
          ├── db.changelog-master.yaml
          └── ddl-v.0.0.1.yaml

2'DO

• Support other databases