ORDER BY

ORDER BY adjusts the order of rows in the alias.

Syntax: ORDER BY <expression> <string>, <expression> <string>, ...
Input:

• <expression>: Sorting criterion; multiple criteria must be homologous and are operated from left to right
• <alias>: Fashion of sorting, either ASC or DESC (case insensitive), or ASC when omitted

For instance, adjusts the order of one-step paths path, first into descending radius of terminal-nodes n, then into ascending ID of n if n shares the same radius.

n([4, 2]).e().n(as n) as path
order by n.radius desc, n
return path

Sample graph: (to be used for the following examples)

create().node_schema("student").node_schema("course")
create().node_property(@*, "name").node_property(@student, "age", int32).node_property(@course, "credit", int32)
insert().into(@student).nodes([{_id:"S001", _uuid:1, name:"Jason", age:25}, {_id:"S002", _uuid:2, name:"Lina", age:23}, {_id:"S003", _uuid:3, name:"Eric", age:24}, {_id:"S004", _uuid:4, name:"Emma", age:26}, {_id:"S005", _uuid:5, name:"Pepe", age:24}])
insert().into(@course).nodes([{_id:"C001", _uuid:6, name:"French", credit:4}, {_id:"C002", _uuid:7, name:"Math", credit:5}])
insert().into(@default).edges([{_uuid:1, _from_uuid:1, _to_uuid:6}, {_uuid:2, _from_uuid:2, _to_uuid:6}, {_uuid:3, _from_uuid:3, _to_uuid:6}, {_uuid:4, _from_uuid:2, _to_uuid:7}, {_uuid:5, _from_uuid:3, _to_uuid:7}, {_uuid:6, _from_uuid:4, _to_uuid:7}, {_uuid:7, _from_uuid:5, _to_uuid:7}])

Grouping and Ordering

Example: Find 1-step paths @course-@student, group by course and calculate number of students in each group, and order the results into descening count

n({@course} as a).e().n({@student})
group by a
with count(a) as b
order by b desc 
return table(a.name, b)

| a.name | b |
|--------|---|
| Math   | 4 |
| French | 3 |

Multi-level Ordering

Example: Find 1-step paths @course-@student, order the results into ascending credit of course, then into descending age of student

n({@course} as a).e().n({@student} as b) as p
order by a.credit, b.age desc 
return p{*}

French <---- Jason
French <---- Eric
French <---- Lina
Math <---- Emma
Math <---- Eric
Math <---- Pepe
Math <---- Lina