Home
Extending Informix®Beyond standard relational database objects, HCL Informix® can be extended to handle specialized data types, access methods, routines, and other objects. Informix® includes many built-in extensions that are fully integrated in the database server. Informix® also provides DataBlade® modules, which are packages of extended database objects for a particular purpose and that are installed separately from the database server. Alternatively, you can create your own user-defined objects for Informix®.
Creating extensionsYou can create user-defined data types, routines, access methods, and other database objects to suit your needs. You can use application programming interfaces to write user-defined routines and applications that access data in Informix® databases.
DataBlade® API Programmer's GuideThe Informix® DataBlade® API Programmer's Guide describes information about the DataBlade® API, the C-language application programming interface (API) provided with HCL Informix®.
Database access
Exceptions and eventsThis section describes exceptions and events, and explains how to handle them in DataBlade® API modules.
Event-handling mechanismsAn event-handling mechanism provides a way for one DataBlade® API module to inform another module (or another part of the same module) that an event has occurred during execution of a function.
Invoke a callbackA callback function (or just callback) is a function that you write to handle a particular event.
Register a callbackFor a callback to execute when its associated event occurs, you must register it with the mi_register_callback() function.
Registration duration

Registration duration

The registration of a callback survives until one of the following conditions is met:

The connection on which the callback is registered closes (either the UDR exits or the mi_close() function executes).
The DataBlade® API calls the callback, which happens for state-transition callbacks when one of the following events occurs:
- MI_EVENT_SAVEPOINT
- MI_EVENT_COMMIT_ABORT
- MI_EVENT_POST_XACT
- MI_EVENT_END_STMT
- MI_EVENT_END_XACT
- MI_EVENT_END_SESSION
You explicitly unregister the callback with the mi_unregister_callback() function.

Rate this topic

5 stars 4 stars 3 stars 2 stars 1 star

Comment on this topic.

By clicking this box, you acknowledge that you are NOT a U.S. Federal Government employee or agency, nor are you submitting information with respect to or on behalf of one. HCL provides software and services to U.S. Federal Government customers through its partners immixGroup, Inc. Contact this team at https://hcltechsw.com/resources/us-government-contact. Do not include any personal data in this Comment box.