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22 MySQL ConnectorsThis chapter describes MySQL Connectors, drivers that provide connectivity to the MySQL server for client programs. 22.1 MySQL ODBC SupportMySQL provides support for ODBC by means of MySQL Connector/ODBC, the family of MyODBC drivers. This is the reference for the Connector/ODBC product family of MyODBC drivers that provide ODBC 3.5x compliant access to the MySQL Database System. It will teach you how to install MyODBC and how to use it. You will also information about common programs that are known to work with MyODBC and answers to some of the most frequently asked questions about MyODBC. This reference applies to MyODBC 3.51. You can find a manual for an older version of MyODBC in the binary or source distribution for that version. This is a reference to the MySQL ODBC drivers, not a general ODBC reference. For more information about ODBC, refer to http://www.microsoft.com/data/. The application development part of this reference assumes a good working knowledge of C, general DBMS knowledge, and finally, but not least, familiarity with MySQL. For more information about MySQL functionality and its syntax, refer to http://dev.mysql.com/doc/. If you have questions that are not aswered in this document, please send a mail message to myodbc@lists.mysql.com. 22.1.1 Introduction to MyODBC22.1.1.1 What is ODBC?ODBC (Open Database Connectivity) provides a way for client programs to access a wide range of databases or data sources. ODBC is a standardized API that allows connections to SQL database servers. It was developed according to the specifications of the SQL Access Group and defines a set of function calls, error codes, and data types that can be used to develop database-independent applications. ODBC usually is used when database independence or simultaneous access to different data sources is required. For more information about ODBC, refer to http://www.microsoft.com/data/. 22.1.1.2 What is Connector/ODBC?Connector/ODBC is the term designating the MySQL AB product family of MySQL ODBC drivers. These are known as the MyODBC drivers. 22.1.1.3 What is MyODBC 2.50?MyODBC 2.50 is a 32-bit ODBC driver from MySQL AB that is based on ODBC 2.50 specification level 0 (with level 1 and 2 features). This is one of the most popular ODBC drivers in the Open Source market, used by many users to access the MySQL functionality. 22.1.1.4 What is MyODBC 3.51?MyODBC 3.51 is a 32-bit ODBC driver, also known as the MySQL ODBC 3.51 driver. This version is enhanced compared to the existing MyODBC 2.50 driver. It has support for ODBC 3.5x specification level 1 (complete core API + level 2 features) in order to continue to provide all functionality of ODBC for accessing MySQL. 22.1.1.5 Where to Get MyODBCMySQL AB distributes all its products under the General Public License (GPL). You can get a copy of the latest version of MyODBC binaries and sources from the MySQL AB Web site http://dev.mysql.com/downloads/. For more information about MyODBC, visit http://www.mysql.com/products/myodbc/. For more information about licensing, visit http://www.mysql.com/company/legal/licensing/. 22.1.1.6 Supported PlatformsMyODBC can be used on all major platforms supported by MySQL, such as:
If a binary distribution is not available for downloading for a particular platform, you can build the driver yourself by downloading the driver sources. You can contribute the binaries to MySQL by sending a mail message to myodbc@lists.mysql.com, so that it becomes available for other users. 22.1.1.7 MyODBC Mailing ListMySQL AB provides assistance to the user community by means of its mailing lists. For MyODBC-related issues, you can get help from experienced users by using the myodbc@lists.mysql.com mailing list. For information about subscribing to MySQL mailing lists or to browse list archives, visit http://lists.mysql.com/. Of particular interest is the ODBC forum in the MySQL Connectors section of the forums. 22.1.1.8 MyODBC ForumCommunity support from experienced users is available through the MySQL Forums, located at http://forums.mysql.com. 22.1.1.9 How to Report MyODBC Problems or Bugs
If you encounter difficulties or problems with MyODBC, you should start
by making a log file from the
Check the MyODBC trace file to find out what could be wrong.
You should be able to determine what statements were issued by searching for
the string
You should also try issuing the statements from the
If you find out something is wrong, please only send the relevant rows
(maximum 40 rows) to the
If you are unable to find out what's wrong, the last option is to
create an archive in If you can create a program that also demonstrates the problem, please include it in the archive as well. If the program works with some other SQL server, you should include 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. 22.1.1.10 How to Submit a MyODBC PatchYou can send a patch or suggest a better solution for any existing code or problems by sending a mail message to myodbc@lists.mysql.com. 22.1.2 General Information About ODBC and MyODBC22.1.2.1 Introduction to ODBCOpen Database Connectivity (ODBC) is a widely accepted application-programming interface (API) for database access. It is based on the Call-Level Interface (CLI) specifications from X/Open and ISO/IEC for database APIs and uses Structured Query Language (SQL) as its database access language. A survey of ODBC functions supported by MyODBC is given at section 22.1.16 MyODBC API Reference. For general information about ODBC, see http://www.microsoft.com/data/. 22.1.2.2 MyODBC ArchitectureThe MyODBC architecture is based on five components, as shown in the following diagram:
22.1.2.3 ODBC Driver ManagersAn ODBC Driver Manager is a library that manages communication between the ODBC aware application and driver(s). Its main functionality includes:
The following driver managers are commonly used:
MyODBC 3.51 also is shipped with UnixODBC beginning with version 2.1.2. 22.1.2.4 Types of MySQL ODBC DriversMySQL AB supports two Open Source ODBC drivers for accessing MySQL functionality through the ODBC API: MyODBC (MyODBC 2.50) and MySQL ODBC 3.51 Driver (MyODBC 3.51). Note: From this section onward, we refer both the drivers generically as MyODBC. Whenever there is a difference, we use the original names. 22.1.3 How to Install MyODBCMyODBC works on Windows 9x, Me, NT, 2000, XP, and 2003, and on most Unix platforms. MyODBC is Open Source. You can find the newest version at http://dev.mysql.com/downloads/connector/odbc/. Please note that the 2.50.x versions are LGPL licensed, whereas the 3.51.x versions are GPL licensed. If you have problem with MyODBC and your program also works with OLEDB, you should try the OLEDB driver. Normally you need to install MyODBC only on Windows machines. You need MyODBC for Unix only if you have a program like ColdFusion that is running on a Unix machine and uses ODBC to connect for database access. If you want to install MyODBC on a Unix box, you will also need an ODBC manager. MyODBC is known to work with most Unix ODBC managers.
Notice that other configuration options are shown on the MySQL screen that you can try if you run into problems (options such as trace, don't prompt on connect, and so forth). 22.1.4 Installing MyODBC from a Binary Distribution on Windows
To install MyODBC on Windows, you should download the appropriate
distribution file from http://dev.mysql.com/downloads/connector/odbc/,
unpack it, and execute the On Windows, you may get the following error when trying to install the older MyODBC 2.50 driver: 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 is that some other program is using ODBC. Because of how
Windows is designed, you may not be able in this case to install new
ODBC drivers with Microsoft's ODBC setup program. In most cases, you can
continue by pressing 22.1.5 Installing MyODBC from a Binary Distribution on Unix22.1.5.1 Installing MyODBC from an RPM Distribution
To install or upgrade MyODBC from an RPM distribution on
Linux, simply download the RPM distribution of the latest version
of MyODBC and follow the instructions below. Use If you are installing for the first time: shell> su root shell> rpm -ivh MyODBC-3.51.01.i386-1.rpm If the driver already exists, upgrade like this: shell> su root shell> rpm -Uvh MyODBC-3.51.01.i386-1.rpm
If there is any dependancy error for MySQL client library,
This installs the driver libraries and related documents to `/usr/local/lib' and `/usr/share/doc/MyODBC' respectively. Now proceed onto section 22.1.9.3 Configuring a MyODBC DSN on Unix.
To uninstall the driver, become shell> su root shell> rpm -e MyODBC 22.1.5.2 Installing MyODBC from a Binary Tarball DistributionTo install the driver from a tarball distribution (`.tar.gz' file), download the latest version of the driver for your operating system and follow these steps: shell> su root shell> gunzip MyODBC-3.51.01-i686-pc-linux.tar.gz shell> tar xvf MyODBC-3.51.01-i686-pc-linux.tar shell> cd MyODBC-3.51.01-i686-pc-linux Read the installation instructions in the `INSTALL-BINARY' file and execute these commands. shell> cp libmyodbc* /usr/local/lib shell> cp odbc.ini /usr/local/etc shell> export ODBCINI=/usr/local/etc/odbc.ini Then proceed on to section 22.1.9.3 Configuring a MyODBC DSN on Unix to configure the DSN for MyODBC. For more information, refer to the `INSTALL-BINARY' file that comes with your distribution. 22.1.6 Installing MyODBC from a Source Distribution on Windows22.1.6.1 Requirements
22.1.6.2 Building MyODBC 3.51
MyODBC 3.51 source distributions include `Makefiles' that
uses To build the driver, use this procedure:
Note:
22.1.6.3 TestingAfter the driver libraries are copied/installed to the system directory, you can test whether the libraries are properly built by using the samples provided in the `samples' subdirectory: C:\> cd samples C:\> nmake -f Makefile all 22.1.6.4 Building MyODBC 2.50The MyODBC 2.50 source distribution includes VC workspace files. You can build the driver using these files (`.dsp' and `.dsw') directly by loading them from Microsoft Visual Studio 6.0 or higher. 22.1.7 Installing MyODBC from a Source Distribution on Unix22.1.7.1 Requirements
Once you have all the required files, unpack the source files to a separate directory and follow the instructions as given below: 22.1.7.2 Typical
|
| 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 | Options that specify how MyODBC should work. See below. |
port | 3306 | The TCP/IP port to use if server is not localhost.
|
stmt | A statement to execute when connecting to MySQL. | |
password | The password for the user account on server.
| |
socket | The Unix socket file or Windows named pipe to connect to if server is localhost.
|
The option argument is used to tell MyODBC that the client isn't 100%
ODBC compliant. On Windows, you normally select options by toggling the
checkboxes in the connection screen, but you can also select them in the
option argument. The following options are listed in the order
in which they appear in the MyODBC connect screen:
| Value | Description |
| 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, MySQL returns ``found rows'' instead. You 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'. (On Unix, the file is `/tmp/myodbc.log'.)
|
| 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 | Enable or disable the dynamic cursor support. (Not allowed in MyODBC 2.50.) |
| 64 | Ignore use of database name in db_name.tbl_name.col_name.
|
| 128 | Force use of ODBC manager cursors (experimental). |
| 256 | Disable the use of extended fetch (experimental). |
| 512 | Pad CHAR columns to full column length.
|
| 1024 | SQLDescribeCol() will return fully qualified column names.
|
| 2048 | Use the compressed client/server 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 be needed but...). |
| 262144 | Disable transactions. |
| 524288 | Enable query logging to `c:\myodbc.sql'(`/tmp/myodbc.sql') file. (Enabled only in debug mode.) |
| 1048576 | Do not cache the results locally in the driver,
instead read from server (mysql_use_result()). This works only for
forward-only cursors. This option is very important in dealing
with large tables when you don't want the driver to cache the
entire result set.
|
| 2097152 | Force the use of Forward-only cursor type. In case
of applications setting the default static/dynamic cursor type, and one
wants driver to use non-cache result sets, then this option will ensure
the forward-only cursor behavior.
|
To select multiple options, add together their values. For example,
setting option to 12 (4+8) gives you debugging without packet limits.
The default `myodbc3.dll' is compiled for optimal performance. If you want to debug MyODBC 3.51 (for example, to enable tracing), you should instead use `myodbc3d.dll'. To install this file, copy `myodbc3d.dll' over the installed `myodbc3.dll' file. Make sure to revert back to the release version of the driver DLL once you are done with the debugging because the debug version may cause performance issues.
For MyODBC 2.50, `myodbc.dll' and `myodbcd.dll' are used instead.
The following table shows some recommended option values for
various configurations:
| Configuration | Option Value |
| Microsoft Access | 3 |
| Microsoft Visual Basic | 3 |
| Large tables with too many rows | 2049 |
| Driver trace generation (Debug mode) | 4 |
| Query log generation (Debug mode) | 524288 |
| Generate driver trace as well as query log (Debug mode) | 524292 |
| Large tables with no-cache results | 3145731 |
Yes. You can connect to the MySQL server using SQLDriverConnect, by
specifying the DRIVER name field. Here are the connection strings
for MyODBC using DSN-Less connection:
For MyODBC 2.50:
ConnectionString = "DRIVER={MySQL};\
SERVER=localhost;\
DATABASE=test;\
USER=venu;\
PASSWORD=venu;\
OPTION=3;"
For MyODBC 3.51:
ConnectionString = "DRIVER={MySQL ODBC 3.51 Driver};\
SERVER=localhost;\
DATABASE=test;\
USER=venu;\
PASSWORD=venu;\
OPTION=3;"
If your programming language converts backslash followed by whitespace to a space, it is preferable to specify the connection string as a single long string, or to use a concatenation of multiple strings that does not add spaces in between. For example:
ConnectionString = "DRIVER={MySQL ODBC 3.51 Driver};"
"SERVER=localhost;"
"DATABASE=test;"
"USER=venu;"
"PASSWORD=venu;"
"OPTION=3;"
Refer to the section 22.1.9.4 Connection Parameters, for the list of connection parameters that can be supplied.
If you want to connect to system A from system B with a username
and password of myuser and mypassword, here is a simple
procedure.
On system A, follow these steps:
GRANT to set up an account with a username of myuser that can
connect from system B using a password of myuser:
GRANT ALL ON *.* to 'myuser'@'B' IDENTIFIED BY 'mypassword';
GRANT statement grants all privileges to user `myuser' for
connecting
from system B using the password mypassword. To execute this statement,
you should be either root on system A (or another user who has
appropriate privileges). For more information about MySQL privileges, refer to
section 5.6 MySQL User Account Management.
On system B, follow these steps:
DSN = remote_test SERVER or HOST = A (or IP address of system A) DATABASE = test (The default database or an appropriate one) USER = myuser PASSWORD = mypasswordTo set up a DSN-less connection, refer to section 22.1.9.5 Connecting Without a Predefined DSN.
DSN=remote_test. If it fails, trace the
MyODBC log, and take the further steps based on the error message
from the log. If you need further assistance, send a detailed mail message
to myodbc@lists.mysql.com.
You can also find a simple HOWTO at http://www.phphelp.com/tutorial/using-myodbc-to-connect-to-a-remote-database.html.
If you encounter difficulties or problems with MyODBC, you should start
by making a log file from the ODBC Manager (the log you get when
requesting logs from ODBC ADMIN) and MyODBC.
To get an ODBC trace through Driver Manager, do the following:
Start, point to Settings, and then click Control
Panel.
Administrative Tools, and then double-click Data Sources
(ODBC), as shown below.
32-bit ODBC or ODBC in the Control Panel.
ODBC Data Source Administrator dialog box appears, as shown
below:
Tracing tab of the ODBC Data Source Administrator
dialog box enables you to configure the way ODBC function calls are
traced.
Tracing tab, the
Driver Manager will log all ODBC function calls for all
subsequently run applications.
Stop Tracing Now. Remember that
while tracing is on, the log file continues to increase in size and
that tracing affects the performance of all your ODBC applications.
Trace option in the
`ODBC.INI' file.
Set the tracing ON or OFF by using TraceFile and
Trace parameters in `odbc.ini' as shown below:
TraceFile = /tmp/odbc.trace Trace = 1
TraceFile specifies the name and full path of the trace file
and Trace is set to ON or OFF. You can also use
1 or YES for ON and 0 or NO for
OFF. If you are using ODBCConfig from unixODBC,
then follow the instructions for tracing unixODBC calls at
HOWTO-ODBCConfig.
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). On
Linux or if you are using DSN-Less connection, then you need to supply
OPTION=4 in the connection string.
MyODBC has been tested with the following applications:
If you know of any other applications that work with MyODBC, please send mail to myodbc@lists.mysql.com about them.
Most programs should work with MyODBC, but for each of those listed here, we have tested it ourselves or received confirmation from some user that it works. Many of the descriptions provide workarounds for problems that you might encounter.
Microsoft Data Access Components) from
http://www.microsoft.com/data/. This will fix a bug in Access that
when you export data to MySQL, the table and column names aren't specified.
Another way to work around this bug is to upgrade to MyODBC 2.50.33 and
MySQL 3.23.x, which together provide a workaround for the problem.
You should also get and apply the Microsoft Jet 4.0 Service Pack 5 (SP5)
which can be found at
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q239114.
This will fix some cases where columns are marked as #DELETED#
in Access.
Note: If you are using MySQL 3.22, you must to apply the
MDAC patch and use MyODBC 2.50.32 or 2.50.34 and up to work around
this problem.
Return
matching rows option. For Access 2.0, you should additionally enable
the Simulate ODBC 1.0 option.
TIMESTAMP, not TIMESTAMP(n),
n < 14.
#DELETED#.
DOUBLE float fields. Access fails when comparing with
single floats. The symptom usually is that new or updated rows may show
up as #DELETED# or that you can't find or update rows.
BIGINT
column, the results will be displayed as #DELETED. The
work around solution is:
TIMESTAMP as the data type.
Change BIGINT columns to INT option in the connection
dialog in ODBC DSN Administrator.
#DELETED#, but newly
added/updated records will be displayed properly.
Another user has changed your data after
adding a TIMESTAMP column, the following trick may help you:
Don't use a table data sheet view. Instead, create a form with the
fields you want, and use that form data sheet view. You should
set the DefaultValue property for the TIMESTAMP column to
NOW(). It may be a good idea to hide the TIMESTAMP column
from view so your users are not confused.
"Query|SQLSpecific|Pass-Through" from the Access menu.
BLOB columns as OLE OBJECTS. If
you want to have MEMO columns instead, you should change BLOB
columns to TEXT with ALTER TABLE.
DATE columns properly. If you have a problem
with these, change the columns to DATETIME.
BYTE, Access will try
to export this as TINYINT instead of TINYINT UNSIGNED.
This will give you problems if you have values larger than 127 in the column.
CursorLocation Property
as adUseServer will return a result of -1 for the
RecordCount Property. To have the right value, you need to set
this property to adUseClient, as shown in the VB code here:
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.CloseAnother workaround is to use a
SELECT COUNT(*) statement
for a similar query to get the correct row count.
Return matching rows option.
Don't optimize column widths and Return matching rows options.
Active property or the
Open method. Note that Active will start by automatically
issuing a SELECT * FROM ... query. That may not be a good thing if
your tables are large.
VARCHAR rather than ENUM, as
it exports the latter in a manner that causes MySQL problems.
CONCAT() function. For example:
SELECT CONCAT(rise_time), CONCAT(set_time)
FROM sunrise_sunset;
Values retrieved as strings this way should be correctly recognized
as time values by Excel97.
The purpose of CONCAT() in this example is to fool ODBC into thinking
the column is of ``string type.'' Without the CONCAT(), ODBC knows the
column is of time type, and Excel does not understand that.
Note that this is a bug in Excel, because it automatically converts a
string to a time. This would be great if the source was a text file, but
is unfortunate when the source is an ODBC connection that reports
exact types for each column.
mysql client command-line tool.
Database tool bar, press the Insert Database button.
Get Data button.
Get Data screen, press the Ms Query
button.
Ms Query, create a new data source using the `my' DSN file.
Return Data to Microsoft Word.
Finish.
Insert Data and select the records.
OK and you see the rows in your Word document.
Don't optimize column width
option 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);
PRIMARY, though this
has not been a problem.
Return matching rows option.
SHOW PROCESSLIST will not work properly. The fix is to use
OPTION=16384 in the ODBC connect string or to select
the Change BIGINT columns to INT option in the MyODBC connect
screen. You may also want to select the Return matching rows option.
BIGINT in your result, you may get the error
[Microsoft][ODBC Driver Manager] Driver does not support this parameter
Try selecting the Change BIGINT
columns to INT option in the MyODBC connect screen.
Don't optimize column widths option.
This section answers MyODBC connection-related questions.
Could Not Load Translator or Setup Library Error OccursFor more information, refer to MS KnowledgeBase Article(Q260558). Also, make sure you have the latest valid `ctl3d32.dll' in your system directory.
Access denied Error Occurs
Refer to section 5.5.8 Causes of Access denied Errors.
Refer to this document about connection pooling: http://support.microsoft.com/default.aspx?scid=kb;EN-US;q169470.
This section of the document answers questions related to MyODBC with Microsoft Access.
The following must be done on your client PC in order to make Microsoft Access work with MyODBC.
Microsoft Data Access Components) from
http://www.microsoft.com/data/. This will fix a bug in Access that
when you export data to MySQL, the table and column names aren't specified.
Another way to work around this bug is to upgrade to MyODBC 2.50.33 and
MySQL 3.23.x, which together provide a workaround for the problem.
You should also get and apply the Microsoft Jet 4.0 Service Pack 5 (SP5)
which can be found at
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q239114.
This will fix some cases where columns are marked as #DELETED#
in Access.
Note: If you are using MySQL 3.22, you must to apply the
MDAC patch and use MyODBC 2.50.32 or 2.50.34 and up to work around
this problem.
Return matching rows
option.
You cannot export a table or query to MySQL unless you have installed MyODBC.
To export a table from Access to MySQL, follow these instructions:
table or query you want to export,
and then in the File menu, select Export.
Export Object Type Object name To dialog box, in the
Save As Type box, select ODBC Databases () as shown here:
Export dialog box, enter a name for the file (or use the
suggested name), and then select OK.
Microsoft Access connects to the MySQL Server through this data source and exports new tables and or data.
You cannot export a table or query to MySQL database unless you have installed the MyODBC.
To import or link a table(s) from MySQL to Access, follow the instructions:
File menu, point to Get External Data,
and then click Import.
To link tables, on the File menu, point to Get External Data, and
then click Link Tables.
Import (or Link) dialog box, in the Files Of Type
box, select ODBC Databases ().
The Select Data Source dialog box lists the defined data sources The Select Data
Source dialog box is displayed; it lists the defined data sources for any ODBC
drivers installed on your computer.
Click either the File Data Source or Machine Data Source tab, and then double-click
the MyODBC or MyODBC 3.51 data source that you want to export to. To
define a new data source for the MyODBC or MyODBC 3.51 driver, please
section 22.1.9.2 Configuring a MyODBC DSN on Windows.
OK.
ODBC data source
and displays the list of tables that you can import or link.
import or link, and then click
OK. If you're linking a table and it doesn't have an index that uniquely
identifies each record, then Microsoft Access displays a list of the fields in
the linked table. Click a field or a combination of fields that will uniquely
identify each record, and then click OK.
Yes. Use the following procedure to view or to refresh links when the structure or location of a linked table has changed. The Linked Table Manager lists the paths to all currently linked tables.
To wiew or refresh links:
Tools menu, point to Add-ins, and then click Linked Table Manager.
Microsoft Access confirms a successful refresh or, if the table wasn't
found, displays the Select New Location of <table name> dialog box
in which you can specify its the table's new location.If several selected
tables have moved to the new location that you specify, the Linked Table
Manager searches that location for all selected tables, and updates all
links in one step.
To vhange the path for a set of linked tables:
Tools menu, point to Add-ins, and then click Linked Table Manager.
Always Prompt For A New Location check box.
OK.
Select New Location of <table name> dialog box, specify the new location, click
Open, and then click OK.
#DELETED#
If the inserted or updated records are shown as #DELETED# in the access, then:
Microsoft Data Access Components) from
http://www.microsoft.com/data/. This will fix a bug in Access that
when you export data to MySQL, the table and column names aren't specified.
Another way to work around this bug is to upgrade to MyODBC 2.50.33 and
MySQL 3.23.x, which together provide a workaround for the problem.
You should also get and apply the Microsoft Jet 4.0 Service Pack 5 (SP5)
which can be found at
http://support.microsoft.com/default.aspx?scid=kb;EN-US;q239114.
This will fix some cases where columns are marked as #DELETED#
in Access.
Note: If you are using MySQL 3.22, you must to apply the
MDAC patch and use MyODBC 2.50.32 or 2.50.34 and up to work around
this problem.
Return
matching rows option. For Access 2.0, you should additionally enable
the Simulate ODBC 1.0 option.
TIMESTAMP, not TIMESTAMP(n),
n < 14.
#DELETED#.
DOUBLE float fields. Access fails when comparing with
single floats. The symptom usually is that new or updated rows may show
up as #DELETED# or that you can't find or update rows.
BIGINT
column, the results will be displayed as #DELETED. The
work around solution is:
TIMESTAMP as the data type.
Change BIGINT columns to INT option in the connection
dialog in ODBC DSN Administrator.
#DELETED#, but newly
added/updated records will be displayed properly.
If you see the following errors,
select the Return Matching Rows option in the DSN configuration
dialog, or specify OPTION=2, as the connection parameter:
Write Conflict. Another user has changed your data. Row cannot be located for updating. Some values may have been changed since it was last read.
This is a strange issue from Access 97, and doesn't appear with Access 2000 or 2002. You can overcome this by upgrading the MyODBC driver to at least MyODBC 3.51.02.
Another user has modified the record that you have modified While Editing Records
With some programs, this error may occur:
Another user has modified the record that you have modified. In most
cases, this can be solved by doing one of the following things:
If these strategies don't help, 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 help you figure out why things go wrong. For instructions, see section 22.1.9.7 Getting an ODBC Trace File.
Read ``How to Trap ODBC Login Error Messages in Access'' at http://support.microsoft.com/support/kb/articles/Q124/9/01.asp?LN=EN-US&SD=gn&FR=0%3CP%3E.
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 will not open. To deal with
this, select the following options:
These add up to a value of 10 (OPTION=10).
Read ``Set the QueryTimeout Value for ODBC Connections'' at http://support.microsoft.com/default.aspx?scid=kb%3Ben-us%3B153756.
Refer to converters section for list of available tools.
This section answers questions related to using MyODBC with Microsoft Visual Basic(ADO, DAO & RDO) and ASP.
SELECT COUNT(*) FROM tbl_name Return an Error?
It's because the COUNT(*) expression is returning a BIGINT,
and ADO can't make sense of a number this big. Select the Change
BIGINT columns to INT option (option value 16384).
AppendChunk() or GetChunk() ADO Methods, I Get an Error Multiple-step operation generated errors. Check each status value.
The GetChunk() and AppendChunk() methods from ADO doesn't work as
expected when the cursor location is specified as adUseServer. On the other
hand, you can overcome this error by using adUseClient.
A simple example can be found from, http://www.dwam.net/iishelp/ado/docs/adomth02_4.htm
You can make use of RecordsAffected property in the ADO execute method. For more
information on the usage of execute method, refer to
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/ado270/htm/mdmthcnnexecute.asp.
Here is an excellent article from Mike Hillyer (m.hillyer@telusplanet.net); explaining how to insert and/or fetch data from blob columns through MyODBC from ADO: MySQL BLOB columns and Visual Basic 6.
Here is yet another good article from Mike Hillyer (m.hillyer@telusplanet.net): How to map Visual basic data type to MySQL types.
A simple examples for the usage of ADO, DAO and RDO with VB can be found her:
If you find any other good example or HOW-TO on ADO/DAO/RDO, then please send the details to myodbc@lists.mysql.com
For more information about how to access MySQL via ASP using MyODBC, refer to the following articles:
A Frequently Asked Questions list for ASP can be found at http://support.microsoft.com/default.aspx?scid=/Support/ActiveServer/faq/data/adofaq.asp.
For information, see ActiveX Data Objects(ADO) Freqently Asked Questions.
This section answers questions related to MyODBC with various ODBC-related tools; such as Microsoft Word, Excel and ColdFusion.
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 database with a table containing two columns of text:
mysql client command-line tool.
Database tool bar, press the Insert Database button.
Get Data button.
Get Data screen, press the Ms Query
button.
Ms Query, create a new data source using the `my' DSN file.
Return Data to Microsoft Word.
Finish.
Insert Data and select the records.
OK and you see the rows in your Word document.
This is an issue similar to that of Access 97 when your table consists
of TEXT or VARCHAR data types. You can fix this error by
upgrading your MyODBC driver to version 3.51.02 or higher.
Refer to MySQL ColdFusion unixODBC MyODBC and Solaris - how to succeed
This section of the document answers questions related to MyODBC general functionality.
AUTO_INCREMENT Column in ODBC
A common problem is how to get the value of an automatically generated ID
from an INSERT statement. With ODBC, you can do something like this (assuming
that auto is an AUTO_INCREMENT field):
INSERT INTO tbl (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 tbl (auto,text) VALUES(NULL,'text'); INSERT INTO tbl2 (id,text) VALUES(LAST_INSERT_ID(),'text');
See section 21.2.13.3 How to 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 WHERE auto IS NULL;
Yes. MyODBC 3.51 supports Dynamic cursor type along with
Forward-only and static.
Due to the performance issues, the driver does not support this feature by
default. You can enable this by specifying the connection option flag as
OPTION=32 or by checking the Enable Dynamic Cursor option
from the DSN configuration.
Transactions are not enabled Errors?The driver returns this error when an application issues any transactional call but the underlying MySQL server either does not support transactions or they are not enabled.
To avoid this problem, you must use a server that has either or both of the
InnoDB or BDB storage engines enabled, and use tables of those
types. MySQL servers from version 4.0 and up support InnoDB by
default. MySQL-Max servers also support BDB on platforms where
BDB is available.
Also, if your server supports transactional table types (InnoDB
and BDB)
make sure the disable transactions option is not set from the DSN
configuration.
Cursor not found Errors?This is becuase the application is using old MyODBC 2.50 version, and it did not set the cursor name explicitly through SQLSetCursorName. The fix is to upgrade to MyODBC 3.51 version.
Yes. If you find something is not working with MyODBC 3.51 that works with MyODBC 2.50, then send a mail message to myodbc@lists.mysql.com
Yes. You can make use of odbc.net to connect to MySQL through MyODBC. Here are the few basic samples to connect to MySQL from VC.NET and VB.NET.
Here is yet another excellent article "Exploring MySQL on .NET environment" by Venu (MyODBC developer) that covers about all MySQL .NET interfaces along with some useful examples.
Caution: Using ODBC.NET with MyODBC, while fetching empty string (0 length), it starts giving the SQL_NO_DATA exception. You can get the patch for this from http://support.microsoft.com/default.aspx?scid=kb;EN-US;q319243.
MyODBC is a lot faster than any other ODBC driver. Slowness might be due to not using the following options.
Interacting with a MySQL server from MyODBC applications involves the following operations:
Most applications use some variation of these steps. The basic application steps are shown in the following diagram:
This section summarizes ODBC routines, categorized by functionality.
For the complete ODBC API reference, please refer to the ODBC Programer's Reference at http://msdn.microsoft.com/library/en-us/odbc/htm/odbcabout_this_manual.asp.
An application can call SQLGetInfo function to obtain conformance
information about MyODBC. To obtain information about support for a specific
function in the driver, an application can call SQLGetFunctions.
Note: For backward compatibility, the MyODBC 3.51 driver supports all deprecated functions.
The following tables list MyODBC API calls grouped by task:
Connecting to a data source:
| Function name | MyODBC | MyODBC | Conformance | Purpose |
| 2.50 | 3.51 | |||
SQLAllocHandle | No | Yes | ISO 92 | Obtains an environment, connection, statement, or descriptor handle. |
SQLConnect | Yes | Yes | ISO 92 | Connects to a specific driver by data source name, user ID, and password. |
SQLDriverConnect | Yes | Yes | ODBC | Connects to a specific driver by connection string or requests that the Driver Manager and driver display connection dialog boxes for the user. |
SQLAllocEnv | Yes | Yes | Deprecated | Obtains an environment handle allocated from driver. |
SQLAllocConnect | Yes | Yes | Deprecated | Obtains a connection handle |
Obtaining information about a driver and data source:
| Function name | MyODBC | MyODBC | Conformance | Purpose |
| 2.50 | 3.51 | |||
SQLDataSources | No | No | ISO 92 | Returns the list of available data sources, handled by the Driver Manager |
SQLDrivers | No | No | ODBC | Returns the list of installed drivers and their attributes, handles by Driver Manager |
SQLGetInfo | Yes | Yes | ISO 92 | Returns information about a specific driver and data source. |
SQLGetFunctions | Yes | Yes | ISO 92 | Returns supported driver functions. |
SQLGetTypeInfo | Yes | Yes | ISO 92 | Returns information about supported data types. |
Setting and retrieving driver attributes:
| Function name | MyODBC | MyODBC | Conformance | Purpose |
| 2.50 | 3.51 | |||
SQLSetConnectAttr | No | Yes | ISO 92 | Sets a connection attribute. |
SQLGetConnectAttr | No | Yes | ISO 92 | Returns the value of a connection attribute. |
SQLSetConnectOption | Yes | Yes | Deprecated | Sets a connection option |
SQLGetConnectOption | Yes | Yes | Deprecated | Returns the value of a connection option |
SQLSetEnvAttr | No | Yes | ISO 92 | Sets an environment attribute. |
SQLGetEnvAttr | No | Yes | ISO 92 | Returns the value of an environment attribute. |
SQLSetStmtAttr | No | Yes | ISO 92 | Sets a statement attribute. |
SQLGetStmtAttr | No | Yes | ISO 92 | Returns the value of a statement attribute. |
SQLSetStmtOption | Yes | Yes | Deprecated | Sets a statement option |
SQLGetStmtOption | Yes | Yes | Deprecated | Returns the value of a statement option |
Preparing SQL requests:
| Function name | MyODBC | MyODBC | Conformance | Purpose |
| 2.50 | 3.51 | |||
SQLAllocStmt | Yes | Yes | Deprecated | Allocates a statement handle |
SQLPrepare | Yes | Yes | ISO 92 | Prepares an SQL statement for later execution. |
SQLBindParameter | Yes | Yes | ODBC | Assigns storage for a parameter in an SQL statement. |
SQLGetCursorName | Yes | Yes | ISO 92 | Returns the cursor name associated with a statement handle. |
SQLSetCursorName | Yes | Yes | ISO 92 | Specifies a cursor name. |
SQLSetScrollOptions | Yes | Yes | ODBC | Sets options that control cursor behavior. |
Submitting requests:
| Function name | MyODBC | MyODBC | Conformance | Purpose |
| 2.50 | 3.51 | |||
SQLExecute | Yes | Yes | ISO 92 | Executes a prepared statement. |
SQLExecDirect | Yes | Yes | ISO 92 | Executes a statement |
SQLNativeSql | Yes | Yes | ODBC | Returns the text of an SQL statement as translated by the driver. |
SQLDescribeParam | Yes | Yes | ODBC | Returns the description for a specific parameter in a statement. |
SQLNumParams | Yes | Yes | ISO 92 | Returns the number of parameters in a statement. |
SQLParamData | Yes | Yes | ISO 92 | Used in conjunction with SQLPutData to supply parameter data at execution time. (Useful for long data values.)
|
SQLPutData | Yes | Yes | ISO 92 | Sends part or all of a data value for a parameter. (Useful for long data values.) |
Retrieving results and information about results:
| Function name | MyODBC | MyODBC | Conformance |