Returns the position of the named column in a result set.
stmt
Specifies a statement resource containing a result set.
column
Specifies the column in the result set. This can either be an integer representing the 0-indexed position of the column, or a string containing the name of the column.
Returns an integer containing the 0-indexed position of the named column in the result set. If the specified column does not exist in the result set, db2_field_num() returns FALSE.