Add support for Spring Data JDBC

[schauder]

The Spring Data JDBC module is approaching its first GA release and I’m wondering what would be the best approach to get Spring Boot support for it.
Relevant resources are:
https://github.com/spring-projects/spring-data-jdbc
https://spring.io/admin/blog/3396-introducing-spring-data-jdbc

A long time ago we created a boot starter for it, which I didn’t update for a long time and which is broken right now: https://github.com/schauder/spring-data-jdbc-boot-starter

[philwebb]

It looks like it won't be too hard to add this. The only slight problem is the naming of the starter since we already have JDBC support without Spring Data.

[snicoll]

spring-boot-starter-jdbc and spring-boot-starter-data-jdbc look like obvious candidates to me. Exposing that on start.spring.io is not that obvious though (if we decide to do so).

[schauder]

I think it should have data-jdbc in the name spring + jdbc without data typically refers to JdbcTemplate & Co

[wilkinsona]

Indeed, and that is what @snicoll has proposed. We already have spring-boot-starter-jdbc and the new starter would be named spring-boot-starter-data-jdbc.

We probably also want a test slice annotation for Data JDBC to go alongside @DataJpaTest, @DataMongTest etc. We already have @JdbcTest for plain JDBC testing. @DataJdbcTest avoids a clash and matches the convention of the other Spring Data-related testing annotations.

[wilkinsona]

I think I've found a bug when multiple Spring Data stores are on the classpath:

Caused by: org.springframework.beans.factory.UnsatisfiedDependencyException: Error creating bean with name 'jdbcMappingContext' defined in class path resource [org/springframework/boot/autoconfigure/data/jdbc/JdbcRepositoriesAutoConfiguration$SpringBootJdbcConfiguration.class]: Unsatisfied dependency expressed through method 'jdbcMappingContext' parameter 1; nested exception is org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type 'org.springframework.data.convert.CustomConversions' available: expected single matching bean but found 3: jdbcCustomConversions,mongoCustomConversions,redisCustomConversions
    at org.springframework.beans.factory.support.ConstructorResolver.createArgumentArray(ConstructorResolver.java:767)
    …

I've raised it with the Spring Data team and am awaiting their input.

[wilkinsona]

@schauder has raised https://jira.spring.io/browse/DATAJDBC-267.