连接池的验证语句。避免被数据库服务器断开

数据库 validationQuery Oracle select 1 from dual DB2 select 1 from sysibm.sysdummy1 mysql select 1 microsoft_sql select 1 hsqldb select 1 from INFORMATION_SCHEMA.SYSTEM_USERS postgresql select version(); ingres select 1 derby select 1 错误

数据库 validationQuery 

Oracle select 1 from dual 

DB2 select 1 from sysibm.sysdummy1 

mysql select 1 

microsoft_sql select 1 

hsqldb select 1 from INFORMATION_SCHEMA.SYSTEM_USERS 

postgresql select version(); 

ingres select 1 

derby select 1 错误，应为:values(1)

H2 select 1