Database Validation Query

SELECT 1 --microsoft sql server (tested on sql-server 9.0, 10.5 [2008])
SELECT 1 FROM INFORMATION_SCHEMA.SYSTEM_USERS -- hsqldb
SELECT 1 FROM rdb$database --firebird
SELECT 1 FROM sysibm.sysdummy1 --db2
SELECT 1 FROM dual -- oracle
SELECT 1 -- postgresql
SELECT 1 -- ingres
SELECT 1 -- mysql
VALUES 1 -- derby
SELECT 1 -- h2

References

• DBCP Database Validation Query