Connection to MySQL via ODBC not working

Question

Hello all together,
I've got a problem with the ODBC connection to MySQL. The connection via ODBC is established and things like tnsping are working.
When I select some data within the SQL*Plus environment, I get no real result. For example "select table_name from all_tables@mysql;" returns nothing.
My entry in listener.ora:
SID_LIST_LISTENER =
(SID_LIST =
(SID_DESC =
(SID_NAME=odbc_mysql)
(ORACLE_HOME=D:\oracle\product\11.0.1\db_1)
(PROGRAM=dg4odbc)
My entry in tnsnames.ora:
MYSQL =
(DESCRIPTION =
(ADDRESS = (PROTOCOL = TCP)(HOST = localhost)(PORT = 1521))
(CONNECT_DATA = (SID=odbc_mysql))
(HS=OK)
The initodbc_mysql.ora in ORACLE_HOME/hs/admin/:
HS_FDS_CONNECT_INFO = odbc_mysql
HS_AUTOREGISTER = TRUE
HS_DB_NAME = hsodbc
I tried some modifications but I still get no data from mysql database. When I try "select * from customer@mysql;" I get the correct number of records, the correct column names, but the content is always "¬¬¬¬". The odbc driver works, because with MS Access I can fetch the data. I'm using Oracle 11g Release 1 EE and MySQL ODBC 5.1.5.
What could be the reason for this?
Greetings,
Joerg

Answer 1

created in my UTF-8 Mysql DB your table and inserted a record; the select shows:
SQL> select * from "movieclass"@mysql;
idClass
ClassName
123
H e l l o
As you can see the content is there, the "space" between the letters is related to unicode. Each character is interpreted by 2 bytes and SQL*Plus wrongly displays both. Using iSQLPLus or SQLDeveloper does not show the "space" between the letters.
Here the data type mapping:
SQL> desc "movieclass"@mysql;
Name Null? Type
idClass NUMBER(3)
ClassName NOT NULL NVARCHAR2(50)
What's the exact version of DG4ODBC you're using? 11.1.0.7?
According to the listener file you're using DG4ODBC on Windows. There was a high/low byte issue in DG4ODBC for Windows. This issue is fixed in 11.1.0.7 and a certain patch. So I recommend you to get first the 11.1.0.7 patchset (if you don't already have it installed):
6890831 Oracle Database Family: Patchset
11.1.0.7.0 PATCH SET FOR ORACLE DATABASE SERVER 11.1.0.7.0
and then please apply also the latest patch:
8689191 Oracle Database Family: Patch
ORACLE 11G 11.1.0.7 PATCH 16 BUG FOR WINDOWS 32 BIT 11.1.0.7.0
There was a high/low byte issue
Edited by: kgronau on Aug 11, 2009 10:28 AM