"Column count does not match" for h2 database Select query using projection in Spring-Boot #DataJpaTest - spring-data-jpa

Question

I have a Spring-Boot app that has some native queries that use content projection. It runs Postgres in production and works fine. I'm trying to set up integration tests for the repositories using #DataJpaTest and a h2 in-memory database, but my queries that are using content projection are failing with a JdbcSQLException out of the driver:
org.h2.jdbc.JdbcSQLException: Column count does not match
I successfully save to the TestEntityManager, so there are records in the database, but I am unable to invoke the SELECT via the repository method. It works properly in production on Postgres -- is this a limitation to h2 and is there a workaround I could apply so I can properly test this?
The repository method looks like this (one inner join, two params in the where clause, table names and columns changed to protect the guilty):
public interface OrderRepository extends PagingAndSortingRepository<Order, Long> {
#Query(nativeQuery = true,
value = "SELECT order.id, order.total, pizza.name " +
"FROM example.order " +
"INNER JOIN example.pizza USING (pizza_id) " +
"WHERE order.customer_id = :custId " +
"AND order.order_date = :orderDate ",
countQuery = "SELECT count(order.id) " +
"FROM example.order " +
"INNER JOIN example.pizza USING (pizza_id) " +
"WHERE order.customer_id = :custId " +
"AND order.order_date = :orderDate")
<T> Page<T> findAllByCustIdAndOrderDate(String custId, OffsetDateTime orderDate, Pageable paging, Class<T> type);
}
And the projection looks like this:
public interface PizzaOrderProjection {
Long getId();
Double getTotal();
String getName();
}
The exception triggers when I call findAllByCustIdAndOrderDate, and the SQL statement that it prints is causing it is the SELECT. The SELECT it prints looks perfectly normal:
Hibernate:
/* dynamic native SQL query */ SELECT
order.id,
order.total,
pizza.name
FROM
example.order
INNER JOIN
example.pizza USING (pizza_id)
WHERE
order.customer_id = ?
AND order.order_date = ? limit ?
2019-04-09 12:42:18.704 WARN 17568 --- [ main] o.h.engine.jdbc.spi.SqlExceptionHelper : SQL Error: 21002, SQLState: 21S02
2019-04-09 12:42:18.708 ERROR 17568 --- [ main] o.h.engine.jdbc.spi.SqlExceptionHelper : Column count does not match; SQL statement:

Answer 1

It turns out that the error message actually has nothing to do with the underlying issue.
The H2 database does not support the using keyword on the inner join clause, only the on keyword.
The issue was resolved by changing the inner join to use on instead, like this:
public interface OrderRepository extends PagingAndSortingRepository<Order, Long> {
#Query(nativeQuery = true,
value = "SELECT order.id, order.total, pizza.name " +
"FROM example.order " +
"INNER JOIN example.pizza ON order.pizza_id = pizza.pizza_id " +
"WHERE order.customer_id = :custId " +
"AND order.order_date = :orderDate ",
countQuery = "SELECT count(order.id) " +
"FROM example.order " +
"INNER JOIN example.pizza ON order.pizza_id = pizza.pizza_id " +
"WHERE order.customer_id = :custId " +
"AND order.order_date = :orderDate")
<T> Page<T> findAllByCustIdAndOrderDate(String custId, OffsetDateTime orderDate, Pageable paging, Class<T> type);
}
This change makes the queries valid in both postgres and h2.