4D Doc Center : INTERSECTION

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4D v14.3

Sets

INTERSECTION


INTERSECTION ( set1 ; set2 ; resultSet )

Parameter	Type	Description
set1	String	First set
set2	String	Second set
resultSet	String	Resulting set

Description

INTERSECTION compares set1 and set2 and selects only the records that are in both. The following table lists all possible results of a set Intersection operation.

Set1	Set2	Result Set
Yes	No	No
Yes	Yes	Yes
No	Yes	No
No	No	No

The graphical result of an Intersection operation is displayed here. The shaded area is the result set.

The resultSet is created by INTERSECTION. The resultSet replaces any existing set having the same name, including set1 and set2. Both set1 and set2 must be from the same table. The resultSet belongs to the same table as set1 and set2. If the same current record is set in both set1 and set2, it remains memorized in the resultSet. Otherwise, resultSet does not have a current record.

4D Server: In Client/Server mode, sets are "visible" depending on their type (interprocess, process and local) and where they were created (server or client). INTERSECTION requires all three sets to be visible on the same machine. See the 4D Server, Sets and Named Selections section in the 4D Server Reference manual for more information.

Example

The following example finds the customers who are served by two sales representatives, Joe and Abby. Each sales representative has a set that represents his or her customers. The customers that are in both sets are represented by both Joe and Abby:

 INTERSECTION("Joe";"Abby";"Both") ` Put customers in both sets in Both

 USE SET("Both") ` Use the set

 CLEAR SET("Both") ` Clear this set but save the others

 DISPLAY SELECTION([Customers]) ` Display customers served by both