出现如上情况在使用pl/sql连接oracle服务器时很常见，问题出现的方式也很多
最终问题还是pl/sql在读取NETWORK\ADMIN\tnsnames.ora是配置的内容时解析错误
也就是说tnsnames.ora文件中的配置有误
如：
192.168.0.246_orcl=
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.246)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME =orcl)
)
)
和
192.168.0.246_orcl=
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.246)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME =orcl)
)
)
就会提示我们遇到的问题： ora-12154 '' TNS:could not resolve the connect identifier specified'
找了很久：http://bbs.csdn.net/topics/390905431从这里看到了结果。一个空格害死人