Oracle bone script, which emerged in the late Shang Dynasty (1600-1046 B.C.), is the earliest mature writing system in China. The source of Chinese characters and the foundation of China's excellent ...

用来设置一个connection在连接池中的存活时间，默认是1800000，即30分钟。如果设置为0，表示存活时间无限大。如果不等于0且小于30秒则会被重置回30分钟。