关于mysql:各类数据库连接探测语句validationQuery

各类数据库的validationQuery语句
DataBase validationQuery

hsqldb select 1 from INFORMATION_SCHEMA.SYSTEM_USERS
Oracle select 1 from dual
DB2 select 1 from sysibm.sysdummy1
MySql select 1
Microsoft SqlServer select1
postgresql select version()
ingres select 1
derby values 1
H2 select 1