The mi_funcarg_get_colno() function

The mi_funcarg_get_colno() function returns the column number for the column associated with the companion-UDR argument of a cost or selectivity function.

Syntax

mi_integer mi_funcarg_get_colno(funcarg_ptr)
   MI_FUNCARG *funcarg_ptr;
funcarg_ptr
A pointer to the MI_FUNCARG structure that describes the companion-UDR argument.
Valid in client LIBMI application? Valid in user-defined routine?
No Yes

Usage

The mi_funcarg_get_colno() function returns the column number of the argument from the MI_FUNCARG structure that funcarg_ptr references. The MI_FUNCARG structure describes an argument of a companion UDR to its cost or selectivity function. Use the mi_funcarg_get_colno() function only for companion-UDR arguments that are column values; that is, only arguments for which the mi_funcarg_get_argtype() function returns the MI_FUNCARG_COLUMN value. The column number is the value from the colid column of the syscolumns system catalog table.
Tip: The system catalog tables refer to the unique number that identifies a column definition as its column identifier. However, the DataBlade® API refers to this number as a column number and the position of a column within the row structure as a column identifier. These two terms do not refer to the same value.

Use the mi_funcarg_get_colno() function in a cost or selectivity function to obtain the column number for the column with which an argument passed into the companion UDR is associated.

Return values

>= 0
The column number for the column associated with the companion-UDR argument.
MI_ERROR
The function was not successful.