Oracle 中调用外部C动态库函数

由于项目为了缩短开发时间，要在Oracle中调用外部已经开发好的C程序。
查找了网上的一些帖子，再结合实际总结这篇文章。希望对大家有所帮助。
参考文章:http://www.cnblogs.com/mathitlin99/archive/2013/09/05/3303717.html

首先编译外部动态库libDialPlan.so

gcc -fPIC -c LibDialPlan.cpp
gcc -shared -o libDialPlan.so LibDialPlan.o -lstdc++

修改Oracle TNS文件和监听文件。
不清楚大家直接拷贝是否可用。如果有问题，请注意一下等号以及括号两边的空格。
tnsnames.ora

ORADB =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.69.166)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = oradb)
    )
  )

EXTPROC_CONNECTION_DATA=
  (DESCRIPTION=
    (ADDRESS_LIST=
    (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
  )
  (CONNECT_DATA=
    (SID = PLSExtProc)
    (PRESENTATION = RO)
  )
  )

listener.ora

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC1521))
      (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.69.166)(PORT = 1521))
    )
  )

ADR_BASE_LISTENER = /home/oracle/db/app


SID_LIST_LISTENER =
(SID_LIST =
  (SID_DESC =
  (GLOBAL_DBNAME = oradb)
  (SID_NAME = oradb)
  )
  (SID_DESC=
  (SID_NAME = PLSExtProc)
  (ORACLE_HOME = /opt/local/oracle/app/product/11.2.0/dbhome_2)
  (ENVS = EXTPROC_DLLS=ANY)
  (PROGRAM = extproc)
  )
)

修改后重启监听:lsnrctl stop ;lsnrctl start
查看监听状态，应该出现如下的监听项:PLSExtProc 

[root@localhost admin]# lsnrctl status

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 04-AUG-2016 19:33:50

Copyright (c) 1991, 2009, Oracle. All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias                     LISTENER
Version TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date                04-AUG-2016 16:23:54
Uptime                    0 days 3 hr. 9 min. 55 sec
Trace Level               off
Security                  ON: Local OS Authentication
SNMP                      OFF
Listener Parameter File /opt/local/oracle/app/product/11.2.0/dbhome_2/network/admin/listener.ora
Listener Log File /opt/local/oracle/app/product/11.2.0/dbhome_2/network/log/listener.log
Listening Endpoints Summary...
  (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
  (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=192.168.69.166)(PORT=1521)))
Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "oradb" has 1 instance(s).
  Instance "oradb", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully
[root@localhost admin]#

创建Oracle  library 对象

create or replace library hytpdtbilldb.Fun_Ext_Proc
  as '/opt/local/Oracle_install/Oracle_Call_External_C/libDialPlan.so';

创建函数
1)按照网上的文章，还有一个parameter的参数。
但是我加入这个参数后一直不能编译通过。去掉后并未影响函数的使用。
2)数字和字符串对应的是binary_integer,varchar2类型。本来C的入参是需要数组类型，但是Oracle没有真正的数组，只能通过字符串代替。
3)在我测试的过程中，偶尔需要重启才能正常调用函数。大家使用的过程中可以留意一下。

create or replace function hytpdtbilldb.Air2Gsi
(x binary_integer,y varchar2)
return varchar2
as
language C
library hytpdtbilldb.Fun_Ext_Proc
name "Air2Gsi";
/