[hibernate-dev] Are the tests in the documentation module expected to run on MySQL only?

[Mark Rotteveel]

Are the tests in the documentation module expected to run on MySQL / 
MariaDB only? Or are they expected to run on all databases?

The test org.hibernate.userguide.mapping.basic.SubselectTest is failing 
on Firebird, because it has the following subselect:

@Subselect(
     "select " +
     "	a.id as id, " +
     "	concat(concat(c.first_name, ' '), c.last_name) as clientName, " +
     "	sum(at.cents) as balance " +
     "from account a " +
     "join client c on c.id = a.client_id " +
     "join account_transaction at on a.id = at.account_id " +
     "group by a.id, concat(concat(c.first_name, ' '), c.last_name)"
)

Firebird doesn't have a concat function. According to the version 
history, this test previously used the SQL standard concat operator 
'||', but this was changed in May with the commit comment "Fix test 
failing on MariaDB".

I am surprised that this change wouldn't be failing on other databases 
either (unless most of them define a concat function next to supporting 
the || operator).

To fix this database independently, it would need to be changed to use 
the JDBC concat function escape:

@Subselect(
     "select " +
     "	a.id as id, " +
     "	{fn concat({fn concat(c.first_name, ' ')}, c.last_name)} as 
clientName, " +
     "	sum(atr.cents) as balance " +
     "from account a " +
     "join client c on c.id = a.client_id " +
     "join account_transaction atr on a.id = atr.account_id " +
     "group by a.id, {fn concat({fn concat(c.first_name, ' ')}, 
c.last_name)}"
)

However, JDBC function escape are (almost) never used in Hibernate 
tests, so I wonder if this would need to be handled elsewhere.

What to do? Do I ignore the documentation tests, add an exception for 
Firebird or create a pull request with the above change, or something else?
-- 
Mark Rotteveel