This section provides help with common queries and areas of functionality in MySQL and how to use them with Connector/ODBC.
Obtaining the value of column that uses
AUTO_INCREMENT after an
INSERT statement can be
achieved in a number of different ways. To obtain the value
immediately after an
SELECT query with the
INSERT INTO tbl (auto,text) VALUES(NULL,'text'); SELECT LAST_INSERT_ID();
If you do not require the value within your application, but
do require the value as part of another
INSERT, the entire process can
be handled by executing the following statements:
INSERT INTO tbl (auto,text) VALUES(NULL,'text'); INSERT INTO tbl2 (id,text) VALUES(LAST_INSERT_ID(),'text');
Certain ODBC applications (including Delphi and Access) may have trouble obtaining the auto-increment value using the previous examples. In this case, try the following statement as an alternative:
SELECT * FROM tbl WHERE auto IS NULL;
Support for the
dynamic cursor is provided
in Connector/ODBC 3.51, but dynamic cursors are not enabled by
default. You can enable this function within Windows by
Enable Dynamic Cursor
checkbox within the ODBC Data Source Administrator.
On other platforms, you can enable the dynamic cursor by
32 to the
value when creating the DSN.
The Connector/ODBC driver has been optimized to provide very fast performance. If you experience problems with the performance of Connector/ODBC, or notice a large amount of disk activity for simple queries, there are a number of aspects you should check:
ODBC Tracing is not
enabled. With tracing enabled, a lot of information is
recorded in the tracing file by the ODBC Manager. You can
check, and disable, tracing within Windows using the
Tracing panel of the ODBC Data
Source Administrator. Within Mac OS X, check the
Tracing panel of ODBC
Section 184.108.40.206, “Getting an ODBC Trace File”.
Make sure you are using the standard version of the driver, and not the debug version. The debug version includes additional checks and reporting measures.
Disable the Connector/ODBC driver trace and query logs. These options are enabled for each DSN, so make sure to examine only the DSN that you are using in your application. Within Windows, you can disable the Connector/ODBC and query logs by modifying the DSN configuration. Within Mac OS X and Unix, ensure that the driver trace (option value 4) and query logging (option value 524288) are not enabled.
For more information on how to set the query timeout on Microsoft Windows when executing queries through an ODBC connection, read the Microsoft knowledgebase document at http://support.microsoft.com/default.aspx?scid=kb%3Ben-us%3B153756.