leinadium » mysql

odbc 3.51 Invalid string or buffer length error

admin — Fri, 23 Jan 2009 11:01:41 +0000

I’m using ODBC 3.51 to connect an ASP scripted site to MySql. I got very strange errors when calling the update function: “Invalid string or buffer length error”.
It turns out that the following line is mandatory for the ODBC driver:

The problem is the CursorLocation, the solution is that sentence

rs.CursorLocation = 3 or rs.CursorLocation = adUseClient

Just in case someone is pulling their hair out over this also…

Will version 3.51 ever update? I’ve seen this version for years and 5.1 has been in alpha for the same amount of time…

MySql Migration Toolkit MSSQL latin1 to MySql utf8

admin — Fri, 23 Jan 2009 10:49:12 +0000

We’ve all been there.
The dreaded Umlaute and special characters have been turned into minced words by some character encoding incompatibility.

When converting a database from MSSQL(2000) to MYSQL (v5) I must have spent days trying to figure this problem out. Some people have come up with very creative albeit complicated solutions:
http://www.oreillynet.com/onlamp/blog/2006/01/turning_mysql_data_in_latin1_t.html

Instead, I found this:
http://forums.mysql.com/read.php?104,124017,124790#msg-124790
Thank you Miguel.
The solution is simple:

In Migration Toolkit’s first step, where you select the source and target db, in Advanced >> option, use the following jdbc connection string for MSSQL:
jdbc:jtds:sqlserver://server:1433/database;user=user;password=password;useUnicode=true;domain=

And this one for MySQL:
jdbc:mysql://server:3306/?user=user&password=password&useServerPrepStmts=false&useUnicode=true

Forget the utf-8 character encoding that you see elsewhere. useUnicode rules. And so does Miguel.

sporadic mysql errors from asp

admin — Fri, 23 Jan 2009 10:45:52 +0000

still, the connection.open errors have crept up each once in a while.
Just implemented the “solution” to kill sleeping mysql processes that are older than x seconds.
Here’s the source: http://www.primaryobjects.com/CMS/Article69.aspx
Rewrote the little function in vbscript and just put it online.
Let’s see what happens.

mysql iis asp and the crazies

admin — Fri, 23 Jan 2009 10:42:56 +0000

It’s been a long time coming.
Here are the error messages of the last two months on Windows IIS6 using ASP 3.0:
The ominous asp error -2147467259:
[MySQL][ODBC 3.51 Driver]Can’t create TCP/IP socket (10038)
[MySQL][ODBC 5.1 Driver]Can’t create TCP/IP socket (10038)
[MySQL][ODBC 3.51 Driver][mysqld-5.0.44-log]MySQL server has gone away

Searching for this error on google and mysql.com would yield results that ranged from other helpless users asking the same question, to mysql admins posting that this is not actually a bug and there’s nothing they can do.

This error would occur sporadically, usually under heavy load and would return relentlessly. Nothing would help!
We tried all the suggestions from various sources (too many to list now), including debugging iis, windows, cleaning up after all connections to the database, mdac updates, tcp/ip ephemeral port range of windows increase, tweaking the registry, etc…

Feeling there’s nothing we could do on the web server platform, we moved on to the db servers (mysql servers 5.x running on debian).
Here we got errors like the following:

Aborted connection 887 to db: ‘abc’ user:
‘abc’ host: ’123.456.789.123′ (Got an error reading communication
packets)

We tried all the fitting suggestion on http://dev.mysql.com/doc/refman/5.1/en/
communication-errors.html without a proper result.
The error returned again and again.
After tweaking several mysql config variables we finally came upon a little noticed post on:
http://themattreid.com/wordpress/?p=15

Thank you matt reid!
Increasing the max_allowed_packet from 8MB to 64 MB did the trick.
Time to celebrate.