[About The Guide]
Add a key to a custom built order
ORDKEYADD([<cOrder> | <nPosition>],
[<cIndexFile>],[<expKeyValue>]) --> lSuccess
<cOrder> | <nPosition> is the name of the order or a number
representing its position in the order list. Using the order name is
the preferred method since the position may be difficult to determine
using multiple-order index files. If omitted or NIL, the controlling
order is assumed.
Specifying an invalid order, such as one that is not custom built, will
raise a runtime error.
<cIndexFile> is the name of an index file, including an optional
drive and directory (no extension should be specified). Use this
argument with <cOrder> to remove ambiguity when there are two or more
orders with the same name in different index files.
If <cIndexFile> is not open by the current process, a runtime error is
<expKeyValue> is a specific key value that you want to add for the
current record. The data type must match that of the order. If not
specified, the order's key expression is evaluated for the current
record and added to the order.
ORDKEYADD() returns true (.T.) if successful; otherwise, it returns
ORDKEYADD() adds keys to a custom built order which is an order that is
not automatically maintained by the DBFCDX driver. You can determine if
an order is custom built using DBORDERINFO(DBOI_CUSTOM, ...). When you
create such an order, it is initially empty. You must then manually add
and delete keys using ORDKEYADD() and ORDKEYDEL().
Note: An existing order can be changed to a custom built order by
using the DBORDERINFO() function.
ORDKEYADD() evaluates the key expression (or <expKeyValue>, if
specified), and then adds the key for the current record to the order.
If the order has a for condition, the key will be added only if that
condition is met, and then only if it falls within the current scoping
Note: You can add several keys for the same record with consecutive
calls to ORDKEYADD().
ORDKEYADD() will fail if:
. The record pointer is positioned on an invalid record (i.e.,
. The specified order is not custom built
. The specified order does not exist
. No order was specified and there is no controlling order
By default, this function operates on the currently selected work area.
It will operate on an unselected work area if you specify it as part of
an aliased expression.
. This example creates a custom index and adds every fiftieth
record to it:
USE Customer VIA "DBFCDX"
// Create custom-built order that is initially empty
INDEX ON LastName TO Last CUSTOM
// Add every 50th record
FOR n := 1 TO RECCOUNT() STEP 50
Files Library is CLIPPER.LIB.
This page created by ng2html v1.05, the Norton guide to HTML conversion utility.
Written by Dave Pearson