Difference between revisions of "Space Race/MATCH Tutorial"

Use MATCH and RETURN to return nodes. Use : to specify what label(s) you wish the returned nodes to have. Not specifying any label will return ALL nodes

Show Institutions instead of Astronauts

MATCH(n:Astronaut) RETURN n;

MATCH(n:Institution) RETURN n; 

When simply matching based on properties of a node, use the {} with the format {property:value}

Return Neil Armstrong's date of birth

MATCH(n:Astronaut{surname:"Gagarin",first_name:"Yuri"})RETURN n.dob;

MATCH(n:Astronaut{surname:"Armstrong",first_name:"Neil"})RETURN n.dob;

ORDER BY works similarly to SQL, defaulting to ordering from low to high value. Adding DESC instead orders the result in descending order

Return the names of the Astronauts ordered by their date of birth, from oldest to youngest.

MATCH(n:Astronaut) RETURN n.first_name, n.surname ORDER BY n.surname;

MATCH(n:Astronaut) RETURN n.first_name, n.surname ORDER BY n.dob;

In Neo4j, rather than empty properties being assigned a value of NULL like in SQL, properties which are not assigned a value do not exist at all

This can be checked using the EXISTS() function

Return the nicknames of the Astronauts who have them in reverse alphabetical order

MATCH(n:Astronaut)WHERE EXISTS(n.middle_names) RETURN n.middle_names; 

MATCH(n:Astronaut)WHERE EXISTS(n.nickname) RETURN n.nickname ORDER BY n.nickname DESC;