How to register non-standarized SQL functions manually in Spring Boot application?

Question

I\'m using JPA query in my current spring-boot project. How can I add non-standardized SQL functions like GROUP_CONCAT?

Prior, to my previo

Answer 1

In case someone is having issues when registering this in a SpringBoot app this is the right way:

Create a class that implements: MetadataBuilderContributor interface.

package com.application.config;

public class SqlFunctionsMetadataBuilderContributor implements MetadataBuilderContributor {

  @Override
  public void contribute(MetadataBuilder metadataBuilder) {
    metadataBuilder.applySqlFunction(
        "STRING_AGG",
        new StandardSQLFunction(
            "STRING_AGG",
            StandardBasicTypes.STRING
        )
    );
  }
}

In your application .yml (or .properties) refer to the previously created class in the following properties path: spring.jpa.properties.hibernate.metadata_builder_contributor

  spring:      
    jpa:
      properties:
        hibernate:
          metadata_builder_contributor: com.application.config.SqlFunctionsMetadataBuilderContributor