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