Efficient SQL test query or validation query that will work across all (or most) databasesMany database connection pooling libraries provide the ability to test their SQL connections for idleness. For example, the JDBC pooling library c3p0 has a property called preferredTestQuery, which gets executed on the connection at configured intervals. Similarly, Apache Commons DBCP has validationQuery. Many example queries I've seen are for MySQL and recommend using SELECT 1; as the value for t
