ODBC

Supported Platforms
ODBC

Windows platforms
UNIX platforms
ODBC Connection Pooling

Windows platforms

General

heitml accesses the databases using ODBC drivers. Many database systems are actually delivered together with ODBC drivers, e.g. Microsoft Access^TM or PostgreSQL. You need ODBC drivers for the operting system you run heitml on and you need 32 or 64 Bit drivers depending on the 32 or 64 bit version of heitml you are using.

Creating Data Sources

To access a database from heitml you must create a data source. The data source must have a unique name. This name has to be specified through the datasource parameter in the heitml configuration file. The data source for the demo application is named "heitml2.1". To create it and to link it to the file \htdocs\heitml2.1\tutor\heitml.mdb in the heitml installation directory perform the following steps:

Click on Start, then Settings, then Control Panel. On Windows XP click the Administrative Tools icon in Control Panel.
In the Control Panel, find the '32-bit ODBC', 'ODBC Data Sources' or 'Data Sources (ODBC)' icon and double-click on it.
In the 'ODBC Data Source Administrator' window, click the 'System DSN' tab.
Now click on the 'Add' button.
Click on the entry 'Microsoft Access Driver (*.mdb)' or the entry with the driver of your favorite database system to highlight it and then click 'Finish'.
In the window coming up, enter "heitml2.1" as the Data Source Name and provide further database specific information. In the case you selected the MS Access^TM ODBC Driver:

Click the 'Select' button
In the Select Database window, first select the Drive where you installed heitml and then select the 'heitml2.1' directory folder (If you installed heitml under a folder other than the default name 'heitml2.1', choose that folder instead.) Look for the file in the \htdocs\heitml2.1\tutor directory called heitml.mdb and click on it to highlight it. Then click OK, which closes the 'Select Database' window.
In the 'ODBC Microsoft Access Setup' window click OK to close it.

In the 'ODBC Data Source Administrator' window click OK to close it.

If your database system requires user authentication, setup a user 'heitml' with password 'heitml' for the database you are going to access through the ODBC data source "heitml2.1" and grant appropriate permissions.

Thread-safe ODBC 32-bit drivers

In a multi-threaded application like an ISAPI compliant Web server, the ODBC driver must be thread-safe. At the time of this writing, all ODBC drivers based on the Microsoft Jet database engine like the Microsoft Access^TM driver are not thread-safe, the Microsoft SQL Server^TM, Oracle and Visual FoxPro ODBC drivers are thread-safe. For more information, see the dbserialize configuration option.

UNIX platforms

How to get ODBC drivers?

At the time of this writing, ODBC Drivers are shipped either

with the latest iODBC (http://www.iodbc.org) distribution,
with the latest unixODBC (http://www.unixodbc.org) distribution,
with Linux distributions like RedHat or SuSE,
or with the latest DataDirect distribution.

heitml has been tested with unixODBC. It is recommended to use unixODBC 2.2.0 or later.

Creating Data Sources

To access a database from heitml you must create an ODBC data source. The data source must have a unique name. This name has to be specified through the datasource parameter in the heitml configuration file. The data source for the demo application is named heitml. The following instructions apply to unixODBC.

To create an ODBC data source, either use the ODBC Administrator of the ODBC distribution, e.g. ODBCConfig, gODBCConfig, use odbcinst, or edit the odbc.ini file.

Creation of an ODBC data source width ODBCConfig is as follows:

issue ODBCConfig from the shell.
In the 'ODBC Data Source Administrator' window, click the 'System DSN' tab.
Now click on the 'Add' button.
Click on the entry with the driver of your favorite database system to highlight it and then click 'Ok'.
In the window coming up, enter heitml as the Data Source Name and provide further database specific information. Depending on the database systen this might require to create a database and database user first.
When you are finished, save your changes and exit.

ODBC Connection Pooling

heitml 2.1 or later supports ODBC Connection Pooling. Note that heitml turns on ODBC Connection Pooling on the process level, even for the ISAPI version. In addition, you have to switch on the connpool configuration option and you have to enable Connection Pooling in the ODBC Data Source Administrator.