How to generate a ddl creation script with a modern Spring Boot + Data JPA and Hibernate setup?
HibernateSpring BootSpring DataSpring Data-JpaHibernate Problem Overview
Currently, I'm using the default @SpringBootApplication
annotation with the following properties in application.properties
:
spring.datasource.url=jdbc:mysql://localhost/dbname
spring.datasource.username=X
spring.datasource.password=X
spring.datasource.driver-class-name=com.mysql.jdbc.Driver
spring.jpa.hibernate.naming_strategy=my.package.CustomNamingStrategy
Since JPA 2.1, I should be able to use the javax.persistence.schema-generation.*
properties, but setting them in my application.properties seems to have no effect.
I've seen examples like this that wire up a whole bunch of extra beans, but they aren't using Mysql. And in any case, doing it like that requires me to configure many options that spring is taking care of for me now.
My goals are to:
- Generate a schema creation sql script in the MYSQL dialect
- without a database connection being required
- Output the script in the build directory
- Also generating hibernate envers tables would be a huge plus.
I do not want to:
- Create/drop schemas on a live database
Lib versions:
hibernate : 4.3.11.FINAL
spring framework : 4.2.5.RELEASE
spring-boot : 1.3.3.RELEASE
spring-data-jpa : 1.10.1.RELEASE // for querydsl 4 support
spring-data-commons: 1.12.1.RELEASE // for querydsl 4 support
(Using gradle, not maven)
Hibernate Solutions
Solution 1 - Hibernate
Ah, right after I posted this question a section of the spring data docs caught my eye:
> 73.5 Configure JPA properties In addition all properties in > spring.jpa.properties.* are passed through as normal JPA properties > (with the prefix stripped) when the local EntityManagerFactory is > created.
So, to answer my own question: prefix the javax.persistence properties with spring.jpa.properties:
spring.jpa.properties.javax.persistence.schema-generation.create-source=metadata
spring.jpa.properties.javax.persistence.schema-generation.scripts.action=create
spring.jpa.properties.javax.persistence.schema-generation.scripts.create-target=create.sql
After doing this, the schema file was generated automatically in the project root.
Solution 2 - Hibernate
This is yml specific configuration for making spring boot generate ddl creation script in root folder:
spring:
jpa:
properties:
javax:
persistence:
schema-generation:
create-source: metadata
scripts:
action: create
create-target: create.sql
Solution 3 - Hibernate
Updating your jpa properties
will generate the scripts for you.
<prop key="javax.persistence.schema-generation.scripts.action">drop-and-create</prop>
<prop key="javax.persistence.schema-generation.scripts.create-target">./create_mssql.sql</prop>
<prop key="javax.persistence.schema-generation.scripts.drop-target">./drop_mssql.sql</prop>
This will generate the scripts in the given location. There are other properties as well which can be used on various use-cases, please refer here
The whole configuration will look like this
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<persistence xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="2.1" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="my-persistence-unit" transaction-type="JTA">
<description>Forge Persistence Unit</description>
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<jta-data-source>java:jboss/datasources/ExampleDS</jta-data-source>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect"/>
<property name="javax.persistence.schema-generation.database.action" value="drop-and-create"/>
<property name="javax.persistence.sql-load-script-source" value="META-INF/data.sql"/>
</properties>
</persistence-unit>
</persistence>