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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_column_count() functionThe mi_column_count() function obtains the number of columns in a row descriptor.

The mi_column_count() function

The mi_column_count() function obtains the number of columns in a row descriptor.

Syntax

mi_integer mi_column_count(row_desc)
   MI_ROW_DESC *row_desc;

row_desc: A pointer to the row descriptor for which to count columns.


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

Usage

A row descriptor can describe the structure of a row in a table or the structure of a row type. From the row descriptor that row_desc references, the mi_column_count() function obtains the column count for either structure:

The number of columns in the row
The number of fields for the row type

Use the mi_column_count() function to process returned row data on a column-by-column (or field-by-field) basis.

For more information about row descriptors, see the HCL OneDB™ DataBlade® API Programmer's Guide.

Return values

>=0: The number of columns or fields in the specified row descriptor.
MI_ERROR: The function was not successful.