Build list columns list

Command group Flag affected Reversible Execute on client Platform(s)
Lists YES YES NO All

Syntax

Build list columns list list-or-row-name ([Clear list])

Options

Clear list If specified, the command empties the current list and defines it to have a single hash variable column before executing

Description

This command builds a list containing the column names and data types of the current or specified list. This information is placed in the current list. If the current list contains one column, it contains the column names only. The current list column headings are ignored, but to obtain all the available information, you define the list with two columns as follows:

Col 1 (Character) Col 2 (Character)
List Column name List Column data type

The Clear list option clears and defines the current list to contain one column, #S5, so the column data types are not returned. With this option, the command becomes reversible.

The flag is cleared if the value of LIST.$linemax prevents a complete list from being built. The following method and the list of data it loads into the list illustrate the typical values produced:

Example

Do iMyList.$define(iPODate,iPONumber,iPOBatched,iSUContact,iITUnitPrice)
Set current list iColsList
Define list {iColName,iColType}
Build list columns list iMyList
; This provides the following values for iColsList
; iPODate - Short date 2000..2099
; iPONumber - Short integer (0 to 255)
; iPOBatched – Boolean
; iSUContact - Character 30
; iITUnitPrice - Number 2 dp
; Or you do the following:
Calculate iColsList as iMyList.$cols.$makelist($ref.$name,$ref.$coltype)