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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_fp_getcolid() functionThe mi_fp_getcolid() accessor function obtains the column identifier of the column that is associated with the user-defined routine from its MI_FPARAM structure.

The mi_fp_getcolid() function

The mi_fp_getcolid() accessor function obtains the column identifier of the column that is associated with the user-defined routine from its MI_FPARAM structure.

Syntax

mi_integer mi_fp_getcolid(fparam_ptr)
   MI_FPARAM *fparam_ptr;

fparam_ptr: A pointer to the associated MI_FPARAM structure.


Valid in client LIBMI application?	Valid in user-defined routine?
No	Yes

Usage

The mi_fp_getcolid() function obtains the column identifier for the user-defined routine that is associated with the fparam_ptr MI_FPARAM structure. The column identifier is the location of the column within the row structure (with the first column starting at offset 0). The column identifier and row structure identify the column with which the UDR invocation is associated. To obtain the row structure, use the mi_fp_getrow() function.

This function is only valid within an assign(), destroy(), or import support function for an opaque data type that contains smart large objects and for multirepresentational opaque types. Before executing the assign(), destroy(), or import function of an opaque data type, the database server automatically obtains the column identifier and row structure and stores them in the MI_FPARAM structure.

With the mi_fp_getcolid() function, you can implement delayed creation or removal of a smart large object:

Delayed creation of a smart large object within the assign() support function
This function returns the column identifier for the column into which you want to store the opaque type.
Delayed removal of a smart large object within the destroy() support function
This function obtains the column identifier for the column from which you want to remove the opaque type.

Important: The mi_fp_getcolid() function is valid only when called from within an assign(), destroy(), or import support function of an opaque data type. Outside the context of an assign() or destroy() function, mi_fp_getcolid() always returns MI_ERROR.

For more information about UDR information in an MI_FPARAM structure, see the HCL OneDB™ DataBlade® API Programmer's Guide.

Return values

>=0: The column identifier of the column with which the UDR is associated.
MI_ERROR: The function was not successful or that it was not called from within an assign(), destroy(), or import support function of an opaque data type.