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19 MySQL ODBC Support

MySQL provides support for ODBC by means of the MyODBC program. This chapter will teach you how to install MyODBC, and how to use it. Here, you will also find a list of common programs that are known to work with MyODBC.

19.1 How To Install MyODBC

MyODBC is a 32-bit ODBC (2.50) level 0 (with level 1 and level 2 features) driver for connecting an ODBC-aware application to MySQL. MyODBC works on Windows95, Windows98, NT, and on most Unix platforms.

MyODBC is in public domain, and you can find the newest version at http://www.mysql.com/downloads/api-myodbc.html.

If you have problem with MyODBC and your program also works with OLEDB, you should try the OLEDB driver that you can find in the Contrib section. See section D Contributed Programs.

Normally you only need to install MyODBC on Windows machines. You only need MyODBC for Unix if you have a program like ColdFusion that is running on the Unix machine and uses ODBC to connect to the databases.

If you want to install MyODBC on a Unix box, you will also need an ODBC manager. MyODBC is known to work with most of the Unix ODBC managers. You can find a list at these in the ODBC-related links section on the MySQL useful links page. See section 1.10 Useful MySQL-related Links.

To install MyODBC on Windows, you should download the appropriate MyODBC .zip file (for Windows or NT/Win2000), unpack it with WINZIP, or some similar program, and execute the SETUP.EXE file.

On Windows/NT you may get the following error when trying to install MyODBC:

An error occurred while copying C:\WINDOWS\SYSTEM\MFC30.DLL. Restart
Windows and try installing again (before running any applications which
use ODBC)

The problem in this case is that some other program is using ODBC and because of how Windows is designed, you may not in this case be able to install a new ODBC drivers with Microsoft's ODBC setup program. In most cases you can continue by just pressing Ignore to copy the rest of the MyODBC files and the final installation should still work. If this doesn't work, the solution is to reboot your computer in ``safe mode`` (Choose this by pressing F8 just before your machine starts Windows during rebooting), install MyODBC, and reboot to normal mode.

Notice that there are other configuration options on the screen of MySQL (trace, don't prompt on connect, etc) that you can try if you run into problems.

19.2 How to Fill in the Various Fields in the ODBC Administrator Program

There are three possibilities for specifying the server name on Windows95:

Example of how to fill in the ODBC setup:

Windows DSN name:   test
Description:        This is my test database
MySql Database:     test
Server:             194.216.84.21
User:               monty
Password:           my_password
Port:

The value for the Windows DSN name field is any name that is unique in your Windows ODBC setup.

You don't have to specify values for the Server, User, Password, or Port fields in the ODBC setup screen. However, if you do, the values will be used as the defaults later when you attempt to make a connection. You have the option of changing the values at that time.

If the port number is not given, the default port (3306) is used.

If you specify the option Read options from C:\my.cnf, the groups client and odbc will be read from the `C:\my.cnf' file. You can use all options that are usable by mysql_options(). See section 24.1.3.159 mysql_options().

19.3 Connect parameters for MyODBC

One can specify the following parameters for MyODBC on the [Servername] section of an ODBC.INI file or through the InConnectionString argument in the SQLDriverConnect() call.

Parameter Default value Comment
user ODBC (on Windows) The username used to connect to MySQL.
server localhost The hostname of the MySQL server.
database The default database
option 0 A integer by which you can specify how MyODBC should work. See below.
port 3306 The TCP/IP port to use if server is not localhost.
stmt A statement that will be executed when connection to MySQL.
password The password for the server user combination.
socket The socket or Windows pipe to connect to.

The option argument is used to tell MyODBC that the client isn't 100% ODBC compliant. On Windows, one normally sets the option flag by toggling the different options on the connection screen but one can also set this in the opton argument. The following options are listed in the same order as they appear in the MyODBC connect screen:

Bit Meaning
1 The client can't handle that MyODBC returns the real width of a column.
2 The client can't handle that MySQL returns the true value of affected rows. If this flag is set then MySQL returns 'found rows' instead. One must have MySQL 3.21.14 or newer to get this to work.
4 Make a debug log in c:\myodbc.log. This is the same as putting MYSQL_DEBUG=d:t:O,c::\myodbc.log in `AUTOEXEC.BAT'
8 Don't set any packet limit for results and parameters.
16 Don't prompt for questions even if driver would like to prompt
32 Simulate a ODBC 1.0 driver in some context.
64 Ignore use of database name in 'database.table.column'.
128 Force use of ODBC manager cursors (experimental).
256 Disable the use of extended fetch (experimental)
512 Pad CHAR fields to full column length.
1024 SQLDescribeCol() will return fully qualifed column names
2048 Use the compressed server/client protocol
4096 Tell server to ignore space after function name and before '(' (needed by PowerBuilder). This will make all function names keywords!
8192 Connect with named pipes to a mysqld server running on NT.
16384 Change LONGLONG columns to INT columns (Some applications can't handle LONGLONG).
32768 Return 'user' as Table_qualifier and Table_owner from SQLTables (experimental)
65536 Read parameters from the client and odbc groups from `my.cnf'
131072 Add some extra safety checks (should not bee needed but...)

If you want to have many options, you should add the above flags! For example setting option to 12 (4+8) gives you debugging without package limits!

The default `MYODBC.DLL' is compiled for optimal performance. If you want to to debug MyODBC (for example to enable tracing), you should instead use MYODBCD.DLL. To install this file, copy `MYODBCD.DLL' over the installed MYODBC.DLL file.

19.4 How to Report Problems with MyODBC

MyODBC has been tested with Access, Admndemo.exe, C++-Builder, Borland Builder 4, Centura Team Developer (formerly Gupta SQL/Windows), ColdFusion (on Solaris and NT with svc pack 5), Crystal Reports, DataJunction, Delphi, ERwin, Excel, iHTML, FileMaker Pro, FoxPro, Notes 4.5/4.6, SBSS, Perl DBD-ODBC, Paradox, Powerbuilder, Powerdesigner 32 bit, VC++, and Visual Basic.

If you know of any other applications that work with MyODBC, please send mail to myodbc@lists.mysql.com about this!

With some programs you may get an error like: Another user has modifies the record that you have modified. In most cases this can be solved by doing one of the following things:

If the above doesn't help, you should do a MyODBC trace file and try to figure out why things go wrong.

19.5 Programs Known to Work with MyODBC

Most programs should work with MyODBC, but for each of those listed below, we have tested it ourselves or received confirmation from some user that it works:

Program
Comment
Access
To make Access work:
ADO
When you are coding with the ADO API and MyODBC you need to put attention in some default properties that aren't supported by the MySQL server. For example, using the CursorLocation Property as adUseServer will return for the RecordCount Property a result of -1. To have the right value, you need to set this property to adUseClient, like is showing in the VB code below:
Dim myconn As New ADODB.Connection
Dim myrs As New Recordset
Dim mySQL As String
Dim myrows As Long

myconn.Open "DSN=MyODBCsample"
mySQL = "SELECT * from user"
myrs.Source = mySQL
Set myrs.ActiveConnection = myconn
myrs.CursorLocation = adUseClient
myrs.Open
myrows = myrs.RecordCount

myrs.Close
myconn.Close
Another workaround is to use a SELECT COUNT(*) statement for a similar query to get the correct row count.
Active server pages (ASP)
You should use the option flag Return matching rows.
BDE applications
To get these to work, you should set the option flags Don't optimize column widths and Return matching rows.
Borland Builder 4
When you start a query you can use the property Active or use the method Open. Note that Active will start by automatically issuing a SELECT * FROM ... query that may not be a good thing if your tables are big!
ColdFusion (On Unix)
The following information is taken from the ColdFusion documentation: Use the following information to configure ColdFusion Server for Linux to use the unixODBC driver with MyODBC for MySQL data sources. Allaire has verified that MyODBC Version 2.50.26 works with MySQL Version 3.22.27 and ColdFusion for Linux. (Any newer version should also work.) You can download MyODBC at http://www.mysql.com/downloads/api-myodbc.html ColdFusion Version 4.5.1 allows you to us the ColdFusion Administrator to add the MySQL data source. However, the driver is not included with ColdFusion Version 4.5.1. Before the MySQL driver will appear in the ODBC datasources drop-down list, you must build and copy the MyODBC driver to `/opt/coldfusion/lib/libmyodbc.so'. The Contrib directory contains the program mydsn-xxx.zip which allows you to build and remove the DSN registry file for the MyODBC driver on Coldfusion applications.
DataJunction
You have to change it to output VARCHAR rather than ENUM, as it exports the latter in a manner that causes MySQL grief.
Excel
Works. Some tips:
Word
To retrieve data from MySQL to Word/Excel documents, you need to use the MyODBC driver and the Add-in Microsoft Query help. For example, create a db with a table containing 2 columns of text:
odbcadmin
Test program for ODBC.
Delphi
You must use BDE Version 3.2 or newer. Set the `Don't optimize column width' option field when connecting to MySQL. Also, here is some potentially useful Delphi code that sets up both an ODBC entry and a BDE entry for MyODBC (the BDE entry requires a BDE Alias Editor that is free at a Delphi Super Page near you. (Thanks to Bryan Brunton bryan@flesherfab.com for this):
fReg:= TRegistry.Create;
  fReg.OpenKey('\Software\ODBC\ODBC.INI\DocumentsFab', True);
  fReg.WriteString('Database', 'Documents');
  fReg.WriteString('Description', ' ');
  fReg.WriteString('Driver', 'C:\WINNT\System32\myodbc.dll');
  fReg.WriteString('Flag', '1');
  fReg.WriteString('Password', '');
  fReg.WriteString('Port', ' ');
  fReg.WriteString('Server', 'xmark');
  fReg.WriteString('User', 'winuser');
  fReg.OpenKey('\Software\ODBC\ODBC.INI\ODBC Data Sources', True);
  fReg.WriteString('DocumentsFab', 'MySQL');
  fReg.CloseKey;
  fReg.Free;

  Memo1.Lines.Add('DATABASE NAME=');
  Memo1.Lines.Add('USER NAME=');
  Memo1.Lines.Add('ODBC DSN=DocumentsFab');
  Memo1.Lines.Add('OPEN MODE=READ/WRITE');
  Memo1.Lines.Add('BATCH COUNT=200');
  Memo1.Lines.Add('LANGDRIVER=');
  Memo1.Lines.Add('MAX ROWS=-1');
  Memo1.Lines.Add('SCHEMA CACHE DIR=');
  Memo1.Lines.Add('SCHEMA CACHE SIZE=8');
  Memo1.Lines.Add('SCHEMA CACHE TIME=-1');
  Memo1.Lines.Add('SQLPASSTHRU MODE=SHARED AUTOCOMMIT');
  Memo1.Lines.Add('SQLQRYMODE=');
  Memo1.Lines.Add('ENABLE SCHEMA CACHE=FALSE');
  Memo1.Lines.Add('ENABLE BCD=FALSE');
  Memo1.Lines.Add('ROWSET SIZE=20');
  Memo1.Lines.Add('BLOBS TO CACHE=64');
  Memo1.Lines.Add('BLOB SIZE=32');

  AliasEditor.Add('DocumentsFab','MySQL',Memo1.Lines);
C++Builder
Tested with BDE Version 3.0. The only known problem is that when the table schema changes, query fields are not updated. BDE, however, does not seem to recognize primary keys, only the index PRIMARY, though this has not been a problem.
Vision
You should use the option flag Return matching rows.
Visual Basic
To be able to update a table, you must define a primary key for the table. Visual Basic with ADO can't handle big integers. This means that some queries like SHOW PROCESSLIST will not work properly. The fix is to set add the option OPTION=16834 in the ODBC connect string or set the Change BIGINT columns to INT option in the MyODBC connect screen. You may also want to set the Return matching rows option.
VisualInterDev
If you get the error [Microsoft][ODBC Driver Manager] Driver does not support this parameter the reason may be that you have a BIGINT in your result. Try setting the Change BIGINT columns to INT option in the MyODBC connect screen.
Visual Objects
You should use the option flag Don't optimize column widths.

19.6 How to Get the Value of an AUTO_INCREMENT Column in ODBC

A common problem is how to get the value of an automatically generated ID from an INSERT. With ODBC, you can do something like this (assuming that auto is an AUTO_INCREMENT field):

INSERT INTO foo (auto,text) VALUES(NULL,'text');
SELECT LAST_INSERT_ID();

Or, if you are just going to insert the ID into another table, you can do this:

INSERT INTO foo (auto,text) VALUES(NULL,'text');
INSERT INTO foo2 (id,text) VALUES(LAST_INSERT_ID(),'text');

See section 24.1.4.3 How Can I Get the Unique ID for the Last Inserted Row?.

For the benefit of some ODBC applications (at least Delphi and Access), the following query can be used to find a newly inserted row:

SELECT * FROM tbl_name WHERE auto IS NULL;

19.7 Reporting Problems with MyODBC

If you encounter difficulties with MyODBC, you should start by making a log file from the ODBC manager (the log you get when requesting logs from ODBCADMIN) and a MyODBC log.

To get a MyODBC log, you need to do the following:

  1. Ensure that you are using myodbcd.dll and not myodbc.dll. The easiest way to do this is to get myodbcd.dll from the MyODBC distribution and copy it over the myodbc.dll, which is probably in your C:\windows\system32 or C:\winnt\system32 directory. Note that you probably want to restore the old myodbc.dll file when you have finished testing, as this is a lot faster than myodbcd.dll.
  2. Tag the `Trace MyODBC' option flag in the MyODBC connect/configure screen. The log will be written to file `C:\myodbc.log'. If the trace option is not remembered when you are going back to the above screen, it means that you are not using the myodbcd.dll driver (see above).
  3. Start your application and try to get it to fail.

Check the MyODBC trace file, to find out what could be wrong. You should be able to find out the issued queries by searching after the string >mysql_real_query in the `myodbc.log' file.

You should also try duplicating the queries in the mysql monitor or admndemo to find out if the error is MyODBC or MySQL.

If you find out something is wrong, please only send the relevant rows (max 40 rows) to myodbc@lists.mysql.com. Please never send the whole MyODBC or ODBC log file!

If you are unable to find out what's wrong, the last option is to make an archive (tar or zip) that contains a MyODBC trace file, the ODBC log file, and a README file that explains the problem. You can send this to ftp://support.mysql.com/pub/mysql/secret. Only we at MySQL AB will have access to the files you upload, and we will be very discrete with the data!

If you can create a program that also shows this problem, please upload this too!

If the program works with some other SQL server, you should make an ODBC log file where you do exactly the same thing in the other SQL server.

Remember that the more information you can supply to us, the more likely it is that we can fix the problem!


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