首先下载instantclient 可以到oracle官网下载，要注册账号，一定要下对应版本的，要不然不成功，
10G,11G版的,我已经传上来了，免费下载:正在上传中，稍等
配置文件tnsnames.ora 这个一个地方一般都放(network/ADMIN)，只有在pl/sql ----->tools-->proferences...------>connection----> oracle home(empty is autodetect) 写上tnsnames.ora的路径（相关路径换成你自已的）
ORCL2 =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = TCP)(HOST = 172.16.100.183)(PORT = 1521))
)
(CONNECT_DATA =
(SERVICE_NAME = orcl)
)
)
ORACLR_CONNECTION_DATA =
(DESCRIPTION =
(ADDRESS_LIST =
(ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
)
(CONNECT_DATA =
(SID = CLRExtProc)
(PRESENTATION = RO)
)
)
设置环境变量（目录换成你自已的）
TNS_ADMIN=D:\soft\oarcleclient\instantclient_11_2
NLS_LANG=SIMPLIFIED CHINESE_CHINA.ZHS16GBK
path=D:\soft\oarcleclient\instantclient_11_2