Nrthugu

In Spring Data JPA we can map an entity to a specific table by using @Table annotation where we can specify schema and name.

But Spring Data JDBC uses a NamingStrategy to map an entity to a table name by converting the entities class name. For example, if we have the entity class named MetricValue then the table should be named metricvalue in default schema. But I need to map MetricValue to the metric_value table in app schema.

Is there any way to override this mapping by annotation or any other?

The naming behavior is defined by the default implementation of the interface NamingStrategy

From reference documentation, section 4.4.3 of version 1.0.2:

When you use the standard implementations of CrudRepository that Spring Data
JDBC provides, they expect a certain table structure. You can tweak that by
providing a NamingStrategy in your application context.

The default implementation has the following behavior (from javadoc version 1.0.2):

Defaults to no schema, table name based on Class and column name based on
RelationalPersistentProperty with name parts of both separated by '_'.

So create a bean which implements NamingStrategy in register it in your application context.

This is an example from @keddok comment:

@Configuration

@EnableJdbcRepositories

public class MetricStoreRepositoryConfig extends JdbcConfiguration {

    @Autowired

    private DataSource dataSource;



    @Bean

    NamedParameterJdbcOperations operations() {

        return new NamedParameterJdbcTemplate(dataSource);

    }



    @Bean

    PlatformTransactionManager transactionManager() {

        return new DataSourceTransactionManager(dataSource);

    }



    @Bean

    NamingStrategy namingStrategy() {

        return new NamingStrategy() {

            @Override

            public String getSchema() {

                return "metric";

            }

        };

    }

}

Spring Data JDBC has it's own @Table annotation and also an @Column one.

You just add the annotation to your entity and specify the name as the value of the annotation.

To give some examples:

@Table("entity") 

class MyEntity {



    private @Column("last_name") String name;



    @Column(value = "entity_id", keyColumn = "entity_index") 

    private List<SomeOtherEntity> someList;

}

This will read and write MyEntity into/from the table entity instead of the default my_entity.
The attribute name will get stored in the column last_name.
And the columns for backreferencing from the some_other_entity to entity will be named entity_id for the foreign key column which normally would be entity (the table name of the referenced table).
And the list index will be stored in entity_index instead of the default entity_key.

I created an issue for improving the documentation.

Use @Table(name = "metric_value").