The binaries for this distribution of Connector/ODBC can now connect to MySQL server accounts that use the PAM or Windows Native Authentication Plugins for authentication. See The PAM Authentication Plugin, and The Windows Native Authentication Plugin. These capabilities result from linking the Connector/ODBC binaries against the MySQL 5.5.16 libmysql rather than the MySQL 5.1 libmysql used previously. The newer libmysql includes the client-side support needed for the server-side PAM and Windows authentication plugins.

Some catalog functions (such as SQLColumns(), SQLStatistics(), and SQLPrimaryKeys()) would only return one row, when called after pre-execution failed. (Bug #12824839)

The CLI installer script mysqlodbc-installer was missing documentation about how to configure the optional data source parameters. (Bug #12810058)

The Install.bat script contained leftover 3.51 information, and did not properly install the 5.1 Connector/ODBC connector. (Bug #12781039)

With the option charset=cp1251 specified in the connection string, the results could be returned as CP1251 or as UTF8 depending on the query. For example, these queries could give results in different code pages:

select if(1=1,'string in cp1251 code page',0) as 'string in cp1251 code page';
select 'string in cp1251 code page' as 'string in cp1251 code page';

(Bug #11765110, Bug #58038)

An off-by-one error, where sqlwcharchr might read one SQLWCHAR after the end of a string. (Bug #61586)

SQLExecute would return SQL_SUCCESS_WITH_INFO instead of SQL_ERROR, when column parameter binding was enabled. (Bug #59772)

The Connector/ODBC driver did not call mysql_thread_end() when a thread ended, which caused error messages like: Error in my_thread_global_end(): 1 threads didn't exit. (Bug #57727)

When using MySQL Connector/ODBC to fetch data, if a net_write_timeout condition occurred, the operation returned the standard "end of data" status, rather than an error. (Bug #39878)

MS Access fields with VARCHAR NOT NULL columns could not be altered. (Bug #31067)