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Extending HCL OneDB™Beyond standard relational database objects, HCL OneDB™ can be extended to handle specialized data types, access methods, routines, and other objects. HCL OneDB™ includes many built-in extensions that are fully integrated in the database server. HCL OneDB™ 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 HCL OneDB™.
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 HCL OneDB™ databases.
DataBlade® API Function ReferenceThe HCL OneDB™ DataBlade® API Function Reference describes the DataBlade® API functions and the subset of functions that the DataBlade® API supports.
Function descriptionsThis section gives comprehensive reference information about the functions that are valid within DataBlade® API modules. It lists the function descriptions in alphabetical order, with syntax, usage information, and return values for the functions.
The mi_set_connection_user_data() functionThe mi_set_connection_user_data() function associates the address of user data with an open connection.

The mi_set_connection_user_data() function

The mi_set_connection_user_data() function associates the address of user data with an open connection.

Syntax

mi_integer mi_set_connection_user_data(conn, user_data_ptr)
   MI_CONNECTION *conn;
   void *user_data_ptr;

conn: A pointer to a connection descriptor established by a previous call to mi_open(), mi_server_connect(), or mi_server_reconnect().
The value can be a pointer to a session-duration connection descriptor established by a previous call to mi_get_session_connection(). Use of a session-duration connection descriptor is an advanced feature of the DataBlade® API.
user_data_ptr: A pointer to user data to associate with the specified connection.


Valid in client LIBMI application?	Valid in user-defined routine?
Yes	Yes

Usage

The mi_set_connection_user_data() function assigns the user-data pointer that user_data_ptr references to the connection descriptor that conn references. The user-data pointer is the address to a user-defined buffer or structure that contains private information you want to keep with the specified connection.

The DataBlade API does not interpret or touch the associated user-data pointer, other than to store it in the connection descriptor. Cast the user_data_ptr pointer to void * before you store it as user data in a connection descriptor.

You can obtain the user-data pointer from a connection descriptor with the mi_set_connection_user_data() function.

Important: Session-duration function descriptors and named memory are advanced features of the DataBlade API. They can adversely affect your UDR if you use them incorrectly. Use them only when a regular function descriptor cannot perform the task you need done. For more information, see the HCL OneDB™ DataBlade API Programmer's Guide.

Return values

MI_OK: The function was successful.
MI_ERROR: The function was not successful.