Oracle dblink MySQL

下载安装包

需要下载两个安装包unixODBC-2.3.7和mysql-Connector-ODBC 5.3.13
unixODBC源码包http://www.unixodbc.org/unixODBC-2.3.7.tar.gz
mysql-connector-odbc-5.3.13包https://dev.mysql.com/downloads/connector/odbc
版本：5.3.13
平台：Linux - Generic
下载：mysql-connector-odbc-5.3.13-linux-glibc2.12-x86-64bit.tar.gz

安装unixODBC

1	yum install unixODBC*

或

tar -zxf unixODBC-2.3.7.tar.gz
cd unixODBC-2.3.7
./configure --prefix=/usr/local/unixODBC-2.3.7 --includedir=/usr/include --libdir=/usr/local/lib -bindir=/usr/bin --sysconfdir=/usr/local/etc
make && make install

安装mysql-connector-odbc（odbc 5.3及以上是libmyodbc5a.so和libmyodbc5w.so。其中c5a是Ansi版，c5w是Unicode版）

tar -zxf mysql-connector-odbc-5.3.13-linux-glibc2.12-x86-64bit.tar.gz
cd mysql-connector-odbc-5.3.13-linux-glibc2.12-x86-64bit/lib
cp libmyodbc5w.so /usr/local/lib
cd ..
cd bin

注册驱动

1	./myodbc-installer -d -a -n "MySQL ODBC 5.3 Driver" -t "DRIVER=/usr/lib/libmyodbc5w.so;SETUP=/usr/lib/libmyodbc5w.so"

配置odbc

编辑文件odbc.ini,把下面的内容加上去

1	vi /etc/odbc.ini

[mysqldb]
Driver      = /usr/local/lib/libmyodbc5w.so
Description = MyODBC 5 Driver DSN
SERVER      = 192.168.1.71
PORT        = 3306
USER        = root
Password    = root
Database    = test
OPTION      = 3
charset=UTF8

测试

1	isql mysqldb -v

配置Oracle

database gateway for odbc简称dg4odbc
oracle 11.2.0.4默认安装了odbc透明网关
验证

1 2	cd $ORACLE_HOME/hs dg4odbc

hs配置

每个使用dg4odbc的实例，都必须单独一个”init*.ora”文件，文件命名规则：init+<网关sid>+.ora

1 2	cd $ORACLE_HOME/hs/admin vi initmysqldb.ora

HS_FDS_CONNECT_INFO = mysqldb
HS_FDS_TRACE_LEVEL = on
HS_FDS_SHAREABLE_NAME = /usr/lib64/libodbc.so
HS_LANGUAGE= AMERICAN_AMERICA.UTF8
HS_NLS_NCHAR= UCS2
set ODBCINI=/etc/odbc.ini

配置监听器

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

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

ADR_BASE_LISTENER = /data/oracle

SID_LIST_LISTENER=
      (SID_LIST =
       (SID_DESC =
        (GLOBAL_DBNAME = orcl)
        (ORACLE_HOME = /data/oracle/product/11.2.0/db_1)
        (SID_NAME = orcl)
    )
     (SID_DESC =
       (SID_NAME = mysqldb)	#前面定义的SID 
       (ORACLE_HOME = /data/oracle/product/11.2.0/db_1) 
       (PROGRAM = dg4odbc)	#11g为dg4odbc
     )
   )

重启监听后看下myodbc的服务是否已经启动

1	lsnrctl reload

配置tnsnames.ora

1	vi $ORACLE_HOME/network/admin/tnsnames.ora

mysqldb =
   (DESCRIPTION =
     (ADDRESS_LIST =
       (ADDRESS = (PROTOCOL = TCP)(HOST=localhost)(PORT=1521))    
     )
     (CONNECT_DATA =
       (SID = mysqldb)	#前面定义的SID 
     )
     (HS=OK)
   )

创建dblink

1	create public database link mysqldb connect to "root" identified by "root" using 'mysqldb';

检查dblink

1	select * from "test"@mysqldb;

常见问题

SYS@vbox66in>select "id" from t1@myodbc1;
select "id" from t1@myodbc1
*
第 1 行出现错误:
ORA-28500: 连接 ORACLE 到非 Oracle 系统时返回此信息:
[

原因：有一些内容显示不全，检查odbc监听文件，查看HS_LANGUAGE参数，配置为和数据库字符集一致

SYS@vbox66in>select "id" from "t1"@myodbc1;
select "id" from "t1"@myodbc1
*
第 1 行出现错误:
ORA-28500: 连接 ORACLE 到非 Oracle 系统时返回此信息: ORA-28541:
HS 初始化文件的第 8 行发生错误。 ORA-02063:
紧接着 2 lines (起自 MYODBC1)

原因：NVARCHAR/NCHAR和图形数据类型通常以Unicode格式存储数据。unicode字符集因数据库的不同而不同，需要修改HS_NLS_NCHAR=UCS2

SYS@vbox66in>select * from a2@myodbc1;
select * from a2@myodbc1
*
第 1 行出现错误:
ORA-00942: 表或视图不存在
[MySQL][ODBC 5.1 Driver][mysqld-5.7.21-log]Table 'test.A2' doesn't exist
{42S02,NativeErr = 1146}
ORA-02063: 紧接着 2 lines (起自 MYODBC1)

原因：MySQL数据中是区分大小写的，表需要用双引号引起来