8.2.1.1 Microsoft Access

To improve the integration between Microsoft Access and MySQL through Connector/ODBC:

• For all versions of Access, enable the Connector/ODBC Return matching rows option. For Access 2.0, also enable the Simulate ODBC 1.0 option.

• Include a TIMESTAMP column in all tables that you want to be able to update. For maximum portability, do not use a length specification in the column declaration (which is unsupported within MySQL in versions earlier than 4.1).

• Include a primary key in each MySQL table you want to use with Access. If not, new or updated rows may show up as #DELETED#.

• Use only DOUBLE float fields. Access fails when comparing with single-precision floats. The symptom usually is that new or updated rows may show up as #DELETED# or that you cannot find or update rows.

• If you are using Connector/ODBC to link to a table that has a BIGINT column, the results are displayed as #DELETED#. The work around solution is:

  • Have one more dummy column with TIMESTAMP as the data type.

  • Select the Change BIGINT columns to INT option in the connection dialog in ODBC DSN Administrator.

  • Delete the table link from Access and re-create it.

  Old records may still display as #DELETED#, but newly added/updated records are displayed properly.

• If you still get the error Another user has changed your data after adding a TIMESTAMP column, the following trick may help you:

  Do not use a table data sheet view. Instead, create a form with the fields you want, and use that form data sheet view. Set the DefaultValue property for the TIMESTAMP column to NOW(). Consider hiding the TIMESTAMP column from view so your users are not confused.

• In some cases, Access may generate SQL statements that MySQL cannot understand. You can fix this by selecting "Query|SQLSpecific|Pass-Through" from the Access menu.

• On Windows NT, Access reports BLOB columns as OLE OBJECTS. If you want to have MEMO columns instead, change BLOB columns to TEXT with ALTER TABLE.

• Access cannot always handle the MySQL DATE column properly. If you have a problem with these, change the columns to DATETIME.

• If you have in Access a column defined as BYTE, Access tries to export this as TINYINT instead of TINYINT UNSIGNED. This gives you problems if you have values larger than 127 in the column.

• If you have very large (long) tables in Access, it might take a very long time to open them. Or you might run low on virtual memory and eventually get an ODBC Query Failed error and the table cannot open. To deal with this, select the following options:

  • Return Matching Rows (2)

  • Allow BIG Results (8).

  These add up to a value of 10 (OPTION=10).

Some external articles and tips that may be useful when using Access, ODBC and Connector/ODBC:

• Read How to Trap ODBC Login Error Messages in Access

• Optimizing Access ODBC Applications

  • Optimizing for Client/Server Performance

  • Tips for Converting Applications to Using ODBCDirect

  • Tips for Optimizing Queries on Attached SQL Tables