FUNCTION xpxSelectAggrInstances (aggrId                   : AGGREGATE OF GENERIC;
                                 condition                : STRING;
                                 options                  : INTEGER;
                                 firstIndex, maxHits      : INTEGER;
                                 VAR indexOfLastFound     : INTEGER;
                                 VAR actualHits           : INTEGER;
                                 VAR foundInstances       : AGGREGATE OF GENERIC)
                                 status                   : INTEGER;

The xpxSelectAggrInstances function returns a list containing the indexes of all the instances within an aggregate that matches a given Express-X logical expression.

Arguments

1	Type	Name	Comment
2	AGGREGATE OF GENERIC	aggrId	A numeric aggregateID that uniquely identifies the aggregate of interest in the EDMdatabase. This may be any type of aggregate, persistent, volatile or scratch.
3	STRING	condition	A conditional statement, written in Express-X, that the instances shall match. A valid condition is any Express-X logical expression that refers to any number of attributes defined for the type of instance that is stored in the aggregate element. The instances in the aggregate elements may be of different types. Instances that do not possess all the attributes that are being referred to in the <condition> argument will always evaluate to UNKNOWN. These elements are considered not matching. The logical expression may also refer to attributes of referenced instances by using dot-notation. Example conditions: "TRUE" Equivalent to NULL or empty string. "(NAME LIKE JOHN%) AND (AGE > 30)" Maches Johnny and Johnatan if they are older than 30 years. "WIFE.MOTHER.DOG.NAME = Fido" Matches all men with a mother in law that owns a dog named Fido. Note that references to the element it self may be done by the symbol SELF. A string comparing condition may therefore be written "SELF.LastName = SCHMIDT" or simply "LastName = SCHMIDT"
4	INTEGER	options	Not used.
5	INTEGER	firstIndex	The aggregate index from which to start searching for matching instances.
6	INTEGER	maxHits	Specifies the maximum number of matching instances to return.
7	INTEGER	indexOfLastFound	The index of the last found matching instance element. This return value enables incremental search for matching elements. See example below.
8	INTEGER	actualHits	The number of matching instances found.
9	AGGREGATE OF GENERIC	foundInstances	Return value. A numeric aggregateID that uniquely identifies the volatile list that will contain the index of each matching instance.

Return Value

Error rendering macro 'excerpt-include' : User 'null' does not have permission to view the page 'US:_r_XPX_Return_Value'.

Options

Example

firstIndex = 1;
maxHits := 10;
actualHits := maxHits;
 
WHEN (actualHits = maxHits);
BEGIN
indexList := xpfSelectAggrInstances(myAggrId,
"(NAME LIKE JOHN%) AND (AGE > 30)"
0, firstIndex, maxHits, lastMatch,
actualHits,);
 
(* Process matching elements here *)
 
firstIndex := lastMatch + 1;
END;

Arguments

Return Value

Options

Example

See also

Filter by label