ORDSKIPUNIQUE()
Move the record pointer to the next or previous unique key in the controlling
order
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Syntax
ORDSKIPUNIQUE([<nDirection>]) --> lSuccess
Arguments
<nDirection> specifies whether the function will skip to the next or
previous key. Omitting this value or specifying it as 1 causes the
record pointer to skip to the next unique key. Specifying a negative
value makes it skip to the previous key.
Returns
ORDSKIPUNIQUE() returns true (.T.) if successful; otherwise, it returns
false (.F.).
Description
ORDSKIPUNIQUE() allows you to make a non-unique order look like a unique
order. Each time you use ORDSKIPUNIQUE(), you are moved to the next (or
previous) unique key exactly as if you were skipping through a unique
order. This function eliminates the problems associated with
maintaining a unique order, while providing you with fast access to
unique keys.
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.
Examples
. This example uses ORDSKIPUNIQUE() to build an array of unique
last names beginning with the letter "J":
FUNCTION LASTUNIQUE()
LOCAL aLast[0]
SET INDEX TO Last // Use the last name order
? ORDISUNIQUE() // Result: .F.
SET SCOPE TO "J" // Only look at the J's
GO TOP
DO WHILE !EOF() // Add all the unique J
AADD(aLast, Last) // last names to aLast
ORDSKIPUNIQUE()
ENDDO
SET SCOPE TO // Clear the scope
RETURN aLast // Return array of
// unique J names
Files Library is CLIPPER.LIB.
See Also: INDEX ORDISUNIQUE()
