The mi_column_typedesc() function

The mi_column_typedesc() function obtains the type descriptor of the specified column from a row descriptor.

Syntax

MI_TYPE_DESC *mi_column_typedesc(row_desc, column_id)
   MI_ROW_DESC *row_desc;
   mi_integer column_id;
row_desc
A pointer to the row descriptor of the row that contains the column.
column_id
The column identifier, which specifies the position of the column in the specified row descriptor. Column numbering follows C array-indexing conventions: the first column in the row is at position zero.
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_typedesc() function obtains the type descriptor of a column for either structure:
  • The type descriptor for the column at position column_id in the row
  • The type descriptor for the field at position column_id for the row type

The type descriptor is a DataBlade® API structure that provides information about a data type.

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

Return values

An MI_TYPE_DESC pointer
A pointer to the type descriptor for the specified column or field.
NULL
The function was not successful.