oracle如何通過dblink連接mysql

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本周由于公司一個系統的oracle數據庫需要采集另一個系統mysql數據庫的數據，于是對oracle通過dblink連接mysql進行了研究，測試環境是單實例oracle 10g 64位，折騰了半天搞定了，但是生產環境是10g rac，原本以為會很順利，但是折騰了一天多都沒搞定，問題主要出在監聽上面，原本打算放棄，采用中間件連接mysql取數據，但是憑直覺感覺應該是單實例和rac的監聽配置差異造成的，于是在rac節點上單獨創建默認監聽，問題果然解決了。

當配置有問題的時候都會報下面的錯誤：

ORA-28545: error diagnosed by Net8 when connecting to an agent
Unable to retrieve text of NETWORK/NCR message 65535

遇到的主要問題和解決辦法有：

1、oracle 10g 64位的hsodbc應該有問題，文件大小為0，執行hsodbc沒有任何信息；

解決：拷貝32機器下的hsodbc到$ORACLE_HOME/bin目錄下，替換原hsodbc，注意oracle要有權限，下載：http://space.itpub.net/?uid-28321441-action-viewspace-itemid-750733

2、rac監聽不能監聽到hsodbc服務；

解決：netca選擇single node configuration創建監聽來監聽hsodbc服務，監聽端口選擇1522；

3、連接mysql查詢數據亂碼。

解決：編輯/etc/odbc.ini，增加

charset      =gbk
STMT         =SET NAMES 'GBK'

其中gbk是MYSQL字符集。

具體實施步驟如下：

--oracle服務器：
-- 操作系統：Red Hat Enterprise Linux 5.3
-- 數據庫：  Oracle RDBMS 10.2.0.3.0

--mysql服務器：
-- 操作系統：windows server 2003
-- 數據庫：  MySQL 5.5

單實例操作如下，操作都在oracle服務器上完成：

--檢查需要的rpm包，需要的包如下，由于hsodbc應該是只支持32位，所以32位包是必須的：
libtool-ltdl-1.5.22-6.1.i386.rpm
libtool-ltdl-1.5.22-6.1.x86_64.rpm
mysql-5.0.77-3.el5.i386.rpm
mysql-5.0.77-3.el5.x86_64.rpm
mysql-connector-odbc-3.51.26r1127-1.el5.i386.rpm
mysql-connector-odbc-3.51.26r1127-1.el5.x86_64.rpm
perl-DBI-1.52-2.el5.x86_64.rpm
unixODBC-2.2.11-7.1.i386.rpm
unixODBC-2.2.11-7.1.x86_64.rpm

上面unixODBC-2.2.11-7.1、mysql-5.0.77-3.el5、mysql-connector-odbc是需要的包，其他是安裝這些包的前提。
安裝完后檢查
# rpm -qa |grep unixODBC

unixODBC-2.2.11-7.1
unixODBC-2.2.11-7.1

# rpm -qa |grep mysql

mysql-5.0.45-7.el5
mysql-5.0.45-7.el5
mysql-connector-odbc-3.51.26r1127-1.el5
mysql-connector-odbc-3.51.26r1127-1.el5

--編輯/etc/odbc.ini
vi /etc/odbc.ini

#[ODBC Data Sources]
#myodbc3     = MySQL ODBC 3.51 Driver DSN

[test]
Driver       = /usr/lib/libmyodbc3.so
Description  = MySQL ODBC 3.51 Driver DSN
SERVER       = 24.1.20.149
PORT         = 3306
USER         = root
Password     = laopo
Database     = teng_push
OPTION       = 3
SOCKET       =
charset      =gbk
STMT         =SET NAMES 'GBK'

--最后兩個是解決中文亂碼問題，gbk是MYSQL字符集

--切換到oracle用戶
# su - oracle
--編輯環境變量配置文件，主要是LD_LIBRARY_PATH和最后面兩項
$ vi ~/.bash_profile

export ORACLE_BASE=/oracle
export ORACLE_HOME=$ORACLE_BASE/product/10.2.0/db_1
export ORACLE_SID=orcl
export ORACLE_TERM=xterm
export PATH=/usr/sbin:$PATH
export NLS_LANG="SIMPLIFIED CHINESE_CHINA.ZHS16GBK"
#export LANG=zh_CN.GB18030
export PATH=.:$ORACLE_HOME/bin:$ORACLE_HOME/OPatch:$PATH:/bin:/usr/bin:/usr/sbin
:/usr/local/bin:/usr/X11R6/bin
export LD_LIBRARY_PATH=$ORACLE_HOME/lib32:$ORACLE_HOME/lib:/lib:/usr/lib
export CLASSPATH=$ORACLE_HOME/JRE:$ORACLE_HOME/jlib:$ORACLE_HOME/rdbms/jlib
#ulimit -u 16384 -n 65536
umask 022
export EDITOR=vi

ODBCINI=/etc/odbc.ini; export ODBCINI
ODBCSYSINI=/etc; export ODBCSYSINI

--使配置生效
source ~/.bash_profile

--查看odbc版本及參數文件路徑
$odbcinst -j

unixODBC 2.2.11
DRIVERS............: /usr/local/etc/odbcinst.ini
SYSTEM DATA SOURCES: /usr/local/etc/odbc.ini
USER DATA SOURCES..: /usr/local/etc/odbc.ini

--測試 My SQL ODBC 驅動

$isql test -v(測試前需要將/etc/odbc.ini中的Driver= /usr/lib/libmyodbc3.so 修改成/usr/lib64/libmyodbc3.so，測試完后還原)

isql test oracle manager -v
+---------------------------------------+
| Connected!                            |
|                                       |
| sql-statement                         |
| help [tablename]                      |
| quit                                  |
|                                       |
+---------------------------------------+

SQL> quit

--配置 HSODBC 程序
vi $ORACLE_HOME/hs/admin/inittest.ora

HS_FDS_CONNECT_INFO = test
HS_FDS_TRACE_LEVEL = off
HS_FDS_SHAREABLE_NAME=/usr/lib/libmyodbc3.so
set DBCINI=/etc/odbc.ini

--確認 hsodbc 的配置是否正確，如果正確可以看到版本號
--注意：如果是64位oracle,由于hsodbc應該是只支持32位，這里需要拷貝32位機器上的hsodbc到$ORACLE_HOME/bin下替換原有的hsodbc

$ hsodbc

Oracle Corporation --- FRIDAY    DEC 06 2012 12:20:44.240

Heterogeneous Agent Release 10.2.0.3.0 - Production  Built with
   Driver for ODBC

--修改監聽文件，增加下面服務：
    (SID_DESC =
      (PROGRAM = hsodbc)
      (ORACLE_HOME = /oracle/product/10.2.0/db_1)
      (SID_NAME = test)
      (ENVS=LD_LIBRARY_PATH = /oracle/product/10.2.0/db_1/lib32:/usr/lib:/oracle
/product/10.2.0/db_1/lib)
    ) 

$ vi $ORACLE_HOME/network/admin/listener.ora

SID_LIST_LISTENER =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = /oracle/product/10.2.0/db_1)
      (PROGRAM = extproc)
    )
    (SID_DESC =
      (PROGRAM = hsodbc)
      (ORACLE_HOME = /oracle/product/10.2.0/db_1)
      (SID_NAME = test)
      (ENVS=LD_LIBRARY_PATH = /oracle/product/10.2.0/db_1/lib32:/usr/lib:/oracle
/product/10.2.0/db_1/lib)
    ) 
  )

LISTENER =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521))
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
    )
  )

--修改tnsnames.ora
$ vi $ORACLE_HOME/network/admin/tnsnames.ora

test =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS =(PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521)) 
    )    
    (CONNECT_DATA =
      (SID= test)
    )
    (HS=OK) 
  ) 

ORCL =
  (DESCRIPTION =
    (ADDRESS = (PROTOCOL = TCP)(HOST = 127.0.0.1)(PORT = 1521))
    (CONNECT_DATA =
      (SERVER = DEDICATED)
      (SERVICE_NAME = orcl)
    )
  )

EXTPROC_CONNECTION_DATA =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = IPC)(KEY = EXTPROC0))
    )
    (CONNECT_DATA =
      (SID = PLSExtProc)
      (PRESENTATION = RO)
    )
  )

--重啟監聽，要有test服務
$ lsnrctl stop
$ lsnrctl start

Services Summary...
Service "PLSExtProc" has 1 instance(s).
  Instance "PLSExtProc", status UNKNOWN, has 1 handler(s) for this service...
Service "orcl" has 1 instance(s).
  Instance "orcl", status UNKNOWN, has 1 handler(s) for this service...
Service "test" has 1 instance(s).
  Instance "test", status UNKNOWN, has 1 handler(s) for this service...
The command completed successfully

--tnsping測試服務
$ tnsping test

Used TNSNAMES adapter to resolve the alias
Attempting to contact (DESCRIPTION = (ADDRESS_LIST = (ADDRESS =(PROTOCOL = TCP)(HOST = 24.1.20.30)(PORT = 1521))) (CONNECT_DATA = (SID= test)) (HS=OK))
OK (0 msec)

--創建dblink
CREATE PUBLIC DATABASE LINK mysql CONNECT TO "root" IDENTIFIED BY "laopo" USING 'test';

--測試

select * from "emp"@mysql where "id"=1;

至此，單節點配置完成。

rac環境下每個節點都需要配置，和單實例唯一的區別是監聽的配置，我試著多種方式去配置監聽，但都沒有監聽到hsodbc的test服務，最后通過netca選擇single node configuration創建監聽來監聽test服務才成功，注意監聽端口改成1522

rac環境節點1的監聽文件如下：

$vi $ORACLE_HOME/network/admin/listener.ora

SID_LIST_LISTENER_RAC01 =
  (SID_LIST =
    (SID_DESC =
      (SID_NAME = PLSExtProc)
      (ORACLE_HOME = /opt/ora10g/product/10.2.0/db_1)
      (PROGRAM = extproc)
    )
  )

LISTENER_RAC01 =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = rac01-vip)(PORT = 1521)(IP = FIRST))
      (ADDRESS = (PROTOCOL = TCP)(HOST = 24.1.20.246)(PORT = 1521)(IP = FIRST))
    )
  )

SID_LIST_LISTENER1 =
  (SID_LIST =
    (SID_DESC =
      (PROGRAM=hsodbc)
      (ORACLE_HOME=/opt/ora10g/product/10.2.0/db_1)
      (SID_NAME=test)
      (ENVS=LD_LIBRARY_PATH=/opt/ora10g/product/10.2.0/db_1/lib32:/lib:/usr/lib:
/opt/ora10g/product/10.2.0/db_1/lib)
    )
  )

LISTENER1 =
  (DESCRIPTION_LIST =
    (DESCRIPTION =
      (ADDRESS = (PROTOCOL = TCP)(HOST = 24.1.20.246)(PORT = 1522))
    )
  )

上述就是小編為大家分享的oracle如何通過dblink連接mysql實施了，如果剛好有類似的疑惑，不妨參照上述分析進行理解。如果想知道更多相關知識，歡迎關注億速云行業資訊頻道。