Example of cqrs application module

Process of changing table/model structure:

• Create sql script that do what you want
• Update entities
• Update database with Flyway mechanism
• Update meta models (Query Meta Model, Write Meta Model) by QueryDSL maven plugin

Dependencies:

• Flyway - is used as database migration tool.
• Hibernate - is used as ORM in write stack.
• QueryDSL - is used as a tool for type safe SQL-like queries.

Write stack

Uses Hibernate and jpa-querydsl.

Read stack

Uses sql-querydsl with spring-jdbc-extension.

Database - MetaModel synchronization

In brief, to synchroznize database with flyway sql scripts and meta models with database, just run:

mvn -Pdb-tools compile

Database migration with Flyway

• After project is deployed on server, database is automatically initialized and upgreaded. There is no need to use command tool.

• If you want to manually upgread the database. Use command tool:

  mvn -Pdb-tools initialize flyway:init mvn -Pdb-tools initialize flyway:migrate

Generating Query Meta Model

Query meta model is generated from tables from database. It is is generated to src/main/java location, so there is no need to generate automatically by IDE or to generate it during integration tests on hudson.

mvn -Pdb-tools initialize com.mysema.querydsl:querydsl-maven-plugin:export

Generating Command Meta Model

Command Meta Model is generated from JPA entities. It is automatically generated during compile phase to target/generated-sources/querydsljpa directory.

mvn compile