UNION
Adds two collections of the same base type to a new collection.
Syntax | Code Block |
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UNION ( collection1 , collection2 ) |
Inputs
Return type
Venn diagram 
Examples Suppose you have a Parent and a Child entity, where Parent has a multivalued relation with Child via the relation Parent.has_Children. With this model the following instances are created:
| Parent instance | Child instance | Child.name | Child.hobbies |
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| Parent_1 | Child_1 | “Kim” | “Reading”, “Dancing” | | Parent_1 | Child_2 | “Rick” | “Tennis”, “Dancing” | | Parent_1 | Child_3 | “Bob” | “Painting”, “Basketball”, “Reading” | | Parent_2 | Child_4 | “Mary” | “Football” |
| Expression | Result | Type |
|---|
UNION ( Parent[Parent_1].has_Children ,
Parent[Parent_2].Has_Children ) | [ Child_1, Child_2 , Child_3, Child_4 ] | Collection of Child instances | UNION ( Parent[Parent_1].has_Children.name ,
Parent[Parent_2].Has_Children.name ) | [ “Kim”, “Rick”, “Bob”, “Mary” ] | String (multivalued) | | UNION ( Child[Child_2].hobbies , "Reading" ) | [ “Tennis”, “Dancing”, “Reading” ] | String (multivalued) | | UNION ( Child[Child_1].hobbies , Child[Child_2].hobbies ) | [ “Reading”, “Dancing”, “Tennis” ] | String (multivalued) | | UNION( ?, [1, 2] ) | UNKNOWN | Integer (multivalued) |
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