@Test
public void find_movies_johns_friends_have_seen() {
ExecutionEngine engine = new ExecutionEngine(graphDb);
String cql =
"start john=node:users(name = \"John Johnson\") match john-[:IS_FRIEND_OF]->(user)-[:HAS_SEEN]->(movie) return movie;\n";
ExecutionResult result = engine.execute(cql);
logger.info("Execution result:" + result.dumpToString());
}
@Test
public void find_movies_johns_friends_have_seen_but_john_hasnt_seen_CORRECT() {
ExecutionEngine engine = new ExecutionEngine(graphDb);
String cql =
"start john=node:users(name = \"John Johnson\")\n"
+ "match john-[:IS_FRIEND_OF]->(user)-[:HAS_SEEN]->(movie) \n"
+ "optional match john-[r:HAS_SEEN]->(movie)\n"
+ "where r is null\n"
+ "return movie.name;\n";
ExecutionResult result = engine.execute(cql);
logger.info("Execution result:" + result.dumpToString());
}
@Test
// shown for completeness
// this query does not return expected results - see next test for correct solution
public void find_movies_johns_friends_have_seen_but_john_hasnt_seen_INCORRECT() {
ExecutionEngine engine = new ExecutionEngine(graphDb);
String cql =
"start john=node:users(name = \"John Johnson\")\n"
+ "match\n"
+ "john-[:IS_FRIEND_OF]->(user)-[:HAS_SEEN]->(movie),\n"
+ "john-[r:HAS_SEEN]->(movie)\n"
+ "return movie;\n";
ExecutionResult result = engine.execute(cql);
logger.info("Execution result:" + result.dumpToString());
}
