WANT DIFFERENCE operator

Feedback & Requests
2

Hi @clem , is the movie title to be queried is the other way around. Because, I just queried from the movie sample dataset, Matrix and Matrix Revolutions and "The Matrix" has one extra actor. So I think Who all acted in Matrix but not in Matrix Revolutions.

MATCH (p:Person)-[:ACTED_IN]->(m:Movie {title:"The Matrix"})
RETURN p.name,m.title

╒════════════════════╤════════════╕
│"p.name"            │"m.title"   │
╞════════════════════╪════════════╡
│"Emil Eifrem"       │"The Matrix"│
├────────────────────┼────────────┤
│"Hugo Weaving"      │"The Matrix"│
├────────────────────┼────────────┤
│"Laurence Fishburne"│"The Matrix"│
├────────────────────┼────────────┤
│"Carrie-Anne Moss"  │"The Matrix"│
├────────────────────┼────────────┤
│"Keanu Reeves"      │"The Matrix"│
└────────────────────┴────────────┘

MATCH (p:Person)-[:ACTED_IN]->(m:Movie {title:"The Matrix Revolutions"})
RETURN p.name,m.title

╒════════════════════╤════════════════════════╕
│"p.name"            │"m.title"               │
╞════════════════════╪════════════════════════╡
│"Hugo Weaving"      │"The Matrix Revolutions"│
├────────────────────┼────────────────────────┤
│"Laurence Fishburne"│"The Matrix Revolutions"│
├────────────────────┼────────────────────────┤
│"Carrie-Anne Moss"  │"The Matrix Revolutions"│
├────────────────────┼────────────────────────┤
│"Keanu Reeves"      │"The Matrix Revolutions"│
└────────────────────┴────────────────────────┘

Anyways, my method , you can use a List Compression ,

MATCH (p1:Person)-[:ACTED_IN]->(m:Movie {title:"The Matrix"})
with collect (p1.name) as matrix_list
MATCH (p2:Person)-[:ACTED_IN]->(m:Movie {title:"The Matrix Revolutions"})
with collect (p2.name) as matrix_rev_list, matrix_list
return [n in matrix_list WHERE NOT n in matrix_rev_list ] as actors

╒═══════════════╕
│"actors"       │
╞═══════════════╡
│["Emil Eifrem"]│
└───────────────┘

For your debugging of the data

MATCH (p1:Person)-[:ACTED_IN]->(m:Movie {title:"The Matrix"})
with collect (p1.name) as matrix_list
MATCH (p2:Person)-[:ACTED_IN]->(m:Movie {title:"The Matrix Revolutions"})
with collect (p2.name) as matrix_rev_list, matrix_list
return matrix_list, matrix_rev_list

╒═════════════════════════════════════════════════════════════════════════════════════╤═══════════════════════════════════════════════════════════════════════╕
│"matrix_list"                                                                        │"matrix_rev_list"                                                      │
╞═════════════════════════════════════════════════════════════════════════════════════╪═══════════════════════════════════════════════════════════════════════╡
│["Emil Eifrem","Hugo Weaving","Laurence Fishburne","Carrie-Anne Moss","Keanu Reeves"]│["Hugo Weaving","Laurence Fishburne","Carrie-Anne Moss","Keanu Reeves"]│
└─────────────────────────────────────────────────────────────────────────────────────┴───────────────────────────────────────────────────────────────────────┘