背景：64位操作系统中、不安装Oracle-32bit客户端，方便使用PLSQL Developer（不支持64bit位Oracle客户端）

1，下载Oracle简易客户端Instant Client

下载地址：http://www.oracle.com/technetwork/topics/winsoft-085727.html 。 下载instantclient-basic-win32-11.2.0.1.0.zip、instantclient-odbc-win32-11.2.0.1.0.zip

2，安装Instant Client

解压缩下载的两种zip文件。

同时选择两个ZIP文件，，然后右键选择解压到当前目录。

比如解压后我的目录是D:\oracle\product\instantclient_11_2

3，设置环境变量

3.1设置环境变量TNS_ADMIN

TNS_ADMIN比如，=D:\oracle\product\instantclient_11_2\NETWORK\ADMIN。（默认无子目录，NETWORK\ADMIN，手动创建即可)

注：手动创建的子目录NETWORK\ADMIN\下，需要创建文件tnsnames.ora

# tnsnames.ora Network Configuration File: D:\oracle\product\instantclient_11_2\NETWORK\ADMIN\tnsnames.ora
# Generated by Oracle configuration tools.

ORACLR_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
    )
    (CONNECT_DATA =
      (SID = CLRExtProc)
      (PRESENTATION = RO)
    )
  )

ORCL =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 16101218-2)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )

133_NSDEV =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.0.133)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = NSDEV)
    )
  )

3.2设置环境变量NLS_LANG（设置方法如同3.1）

比如NLS_LANG=SIMPLIFIED CHINESE_CHINA.ZHS16GBK

"SIMPLIFIED CHINESE_CHINA.ZHS16GBK"的值，要视情况而定。（select userenv(‘language‘) from dual;）

4，最后一步，设置PLSQL Developer

打开plsqldev.exe，进入菜单tool->Preferences->Connection（工具->首选项->连接），设置如图。