ORACLE 11g 通过odbc建立连接到mysql库的database link

 

以前做过在oracle通过gateway建立到sqlserver的database link（详情参见：https://blog.csdn.net/csdnhsh/article/details/95758865），现在需要无缝访问mysql，所以也需要建立类似这样的连接通道。

 

1、分配mysql账号

先在mysql库上建立连接账号：

 

GRANT SELECT ON test.* TO data_query@'192.168.129.%' IDENTIFIED BY 'data_query_1125';

 

 

 

 

2、安装dg4odbc

 

详细的gateways安装步骤参考http://blog.csdn.net/mchdba/article/details/52719278      里面的 “2、安装模块” 里面有详细的步骤描述。

在安装的时候，有一个关键的选择步骤就是选择odbc组件包进行安装，如下所示：E:\u\oracle\install\pic\11.png，

 

 

 

3、查看下安装的dg4odbc

查看安装是否完成，就直接用莫N股了dg4odbc命令来看

[oracle@hch_test_121_61 ~]$ dg4odbc     Oracle Corporation --- TUESDAY   NOV 15 2016 19:17:19.106   Heterogeneous Agent Release 11.2.0.1.0 - 64bit Production  Built with    Oracle Database Gateway for ODBC     [oracle@hch_test_121_61 ~]$

 

 

 

4、安装mysql组件

准备安装mysql客户端：yum install mysql-connector-odbc.x86_64 -y;

这样会安装一些依赖包主要是

mysql-connector*.x86_64.rpm

unixODBC*.x86_64.rpm

unixODBC*.i386.rpm

 

[root@hch_test_121_90 ~]# yum install mysql-connector-odbc.x86_64 -y Loaded plugins: fastestmirror, security Determining fastest mirrors  * base: ftp.sjtu.edu.cn  * extras: mirrors.163.com  * updates: mirrors.163.com base                                                                                                                                                                    | 3.7 kB     00:00     epel                                                                                                                                                                    | 4.3 kB     00:00     epel/primary_db                                                                                                                                                         | 5.9 MB     00:06     extras                                                                                                                                                                  | 3.4 kB     00:00     updates                                                                                                                                                                 | 3.4 kB     00:00     updates/primary_db                                                                                                                                                      | 3.1 MB     00:00     zabbix                                                                                                                                                                  |  951 B     00:00     zabbix-non-supported                                                                                                                                                    |  951 B     00:00     Setting up Install Process Resolving Dependencies --> Running transaction check ---> Package mysql-connector-odbc.x86_64 0:5.1.5r1144-7.el6 will be installed --> Finished Dependency Resolution   Dependencies Resolved   ===============================================================================================================================================================================================  Package                                               Arch                                    Version                                             Repository                             Size =============================================================================================================================================================================================== Installing:  mysql-connector-odbc                                  x86_64                                  5.1.5r1144-7.el6                                    base                                  114 k   Transaction Summary =============================================================================================================================================================================================== Install       1 Package(s)   Total download size: 114 k Installed size: 345 k Downloading Packages: mysql-connector-odbc-5.1.5r1144-7.el6.x86_64.rpm                                                                                                                        | 114 kB     00:00     Running rpm_check_debug Running Transaction Test Transaction Test Succeeded Running Transaction   Installing : mysql-connector-odbc-5.1.5r1144-7.el6.x86_64                                                                                                                                1/1   Verifying  : mysql-connector-odbc-5.1.5r1144-7.el6.x86_64                                                                                                                                1/1   Installed:   mysql-connector-odbc.x86_64 0:5.1.5r1144-7.el6                                                                                                                                                  Complete! [root@hch_test_121_90 ~]#

 

 

 

5、配置odbc-mysql连接

[root@hch_test_121_90 ~]# more /etc/odbc.ini # Setup from the unixODBC64-libs package [rmt] Driver          = /usr/lib64/libmyodbc5.so Server          = 10.254.3.72 Port            = 3306  User            = data_query  Password        = data_query_1125 Database        = test [root@hch_test_121_90 ~]#

 

 

 

6、测试mysql组件的连接：

[root@hch_test_121_90 ~]#  isql rmt +---------------------------------------+ | Connected!                            | |                                       | | sql-statement                         | | help [tablename]                      | | quit                                  | |                                       | +---------------------------------------+ SQL>

 

 

 

7、配置oracle连接

进去$ORACLE_HOME/hs/admin/，配置initrmt.ora

[oracle@hch_test_121_90 admin]$ more initrmt.ora HS_FDS_CONNECT_INFO=rmt # Data source name in odbc.ini HS_FDS_TRACE_LEVEL= debug HS_FDS_SHAREABLE_NAME=libodbc.so HS_FDS_SUPPORT_STATISTICS=FALSE HS_LANGUAGE=AMERICAN_AMERICA.WE8ISO8859P15 # # ODBC env variables set ODBCINI=/etc/odbc.ini HS_FDS_SHAREABLE_NAME=libodbc.so [oracle@hch_test_121_90 admin]$

 

 

配置$ORACLE_HOME/network/admin/listener.ora

SID_NAME is the DSN for the remote database. 
ORACLE_HOME is the actual Oracle home file path. 
PROGRAM tells Oracle to use heterogeneous services.

 

(SID_DESC =         (SID_NAME = rmt)         (ORACLE_HOME = /home/oracle/app/oracle/product/11.2.0/dbhome_1)         (PROGRAM = dg4odbc)         #(ENVS=LD_LIBRARY_PATH=/usr/lib64:/usr/lib:/home/orared/product/11.2.4/lib:/home/orared/product/11.2.4/odbc/lib)    )

 

 

配置$ORACLE_HOME/network/admin/tnsnams.ora

rmtmysql =   (DESCRIPTION =     (ADDRESS_LIST =       (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.121.90 )(PORT = 1521))     )     (CONNECT_DATA =       (SID = rmt)     )    (HS = OK)   )

 

 

8、建立dblink

create database link tg4mysql connect to data_query identified by "data_query_1125"            using '(DESCRIPTION =            (ADDRESS_LIST =             (ADDRESS = (PROTOCOL = TCP)(HOST = 192.168.121.90)(PORT = 1521))            )            (CONNECT_DATA =              (SID = rmtmysql)            )            (HS = OK)          )';

 

 

 

测试：

SQL>  select * from z_whs@tg4mysql;  select * from z_whs@tg4mysql                      * ERROR at line 1: ORA-28545: error diagnosed by Net8 when connecting to an agent Unable to retrieve text of NETWORK/NCR message 65535 ORA-02063: preceding 2 lines from TG4MYSQL     SQL>

 

解决办法：重启lsnrctl服务

 

 

9、问题ORA-28511

SQL>  select * from Z_WHS@gwmysql; ERROR: ORA-28511: lost RPC connection to heterogeneous remote agent using SID=ORA-28511: lost RPC connection to heterogeneous remote agent using SID=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.121.90)(PORT =1521)))(CONNECT_DATA=(SID=rmt))) ORA-02063: preceding line from GWMYSQL Process ID: 20358 Session ID: 11 Serial number: 46988       no rows selected   SQL>

 

 

再次查看：

SQL> select * from Z_WHS@gwmysql; ERROR: ORA-28511: lost RPC connection to heterogeneous remote agent using SID=ORA-28511: lost RPC connection to heterogeneous remote agent using SID=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.121.90)(PORT =1521)))(CONNECT_DATA=(SID=rmt))) ORA-02063: preceding line from GWMYSQL Process ID: 20497 Session ID: 134 Serial number: 41341       no rows selected   SQL> select ID,cname from Z_WHS@gwmysql; select ID,cname from Z_WHS@gwmysql           * ERROR at line 1: ORA-00904: "CNAME": invalid identifier     SQL> select ID from Z_WHS@gwmysql;            ID ----------           1           2           3   SQL>

 

 

为什么查询单个字段ID能查到记录，查询*查不出记录呢，查看Z_WHS表结构，发现有一个字段cname为小写，尝试改成大写字段，就可以查询出来了。

mysql> show create table Z_WHS; +-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Table | Create Table                                                                                                                                                              | +-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ | Z_WHS | CREATE TABLE `Z_WHS` (   `ID` bigint(20) NOT NULL DEFAULT '0' COMMENT '投诉主题表主键',   `cname` varchar(16) DEFAULT NULL ) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4        | +-------+---------------------------------------------------------------------------------------------------------------------------------------------------------------------------+ 1 row in set (0.00 sec)   mysql> mysql> alter table Z_WHS change  `cname` CNAME varchar(16) DEFAULT NULL;   Query OK, 0 rows affected (38.95 sec) Records: 0  Duplicates: 0  Warnings: 0   mysql>

 

 

# PS：这个时候，oracle的网关对mysql的表是锁定状态，任何对mysql表的dml、ddl操作都会处于等待状态，如下所示：

| 13762502 | root            | localhost             | test         | Query       |       27 | Waiting for table metadata lock                                       | alter table Z_WHS change  `cname` CNAME varchar(16) DEFAULT NULL |

 

需要在oracle的窗口退出来，释放掉通过网关对mysql的锁，才能让mysql窗口的alter语句sesseion会话得到这个表的使用权限来顺利执行完成alter操作。

 

BUT、但是，但是可惜的是alter语句执行完后，select cname 还是报一样的错误出来

 

 

新添加一列数字列：

去mysql库添加数字列 mysql> alter table Z_2 add column NUM int; Query OK, 0 rows affected (0.07 sec) Records: 0  Duplicates: 0  Warnings: 0   mysql> update Z_2 set NUM=1; Query OK, 1 row affected (0.00 sec) Rows matched: 1  Changed: 1  Warnings: 0   mysql>   再通过gateway查询结果： SQL> conn dw/dwys0418 Connected. SQL> select ID,NUM from "Z_2"@gwmysql;            ID       NUM ---------- ----------           1         1   SQL> select ID,NUM,CN from "Z_2"@gwmysql; ERROR: ORA-28511: lost RPC connection to heterogeneous remote agent using SID=ORA-28511: lost RPC connection to heterogeneous remote agent using SID=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=192.168.121.90)(PORT =1521)))(CONNECT_DATA=(SID=rmt))) ORA-02063: preceding line from GWMYSQL Process ID: 21333 Session ID: 11 Serial number: 47108       no rows selected   SQL>

 

问题依旧，等待后续进一步解决。