[orientdb] Install and Usage

• orientdb
• good instruction blog
• install

download community version say, orientdb-community-2.0.9.tar.gz
tar -zxvf orientdb-community-2.0.9.tar.gz
cd orientdb-community-2.0.9
cd bin
./server.sh

• tutorial
  • getting started udemy
  • another tutorial
  • getting started documentations
• SQL+
• python driver
• example query

<create edge via select>
  create edge WorksAt from (select from Person where name="Bob") to (select from Company where name="네이버")

<select & expand>
  select * from V where name = '네이버'
  select expand(in("CeoOf")) from Company where name = '다음카카오'
    : CeoOf class type inlink에 연결된 vertex 
  select expand(in_CeoOf.out) from Company where name = '다음카카오'
    : CeoOf class type inlink의 out vertex
  select name from (select expand(out_MemberOf.in) from V where name = 'John')
    : name이 'John'인 vertex의 MemberOf edge와 연결된 vertex의 name
  select out_Place_Coordinate.in.y from Place where name='제주특별자치도청'
    : 이름이 '제주특별자치도청'인 Place record의 Place_Coordindate type의 out edge를 따라가서
    : 해당 record의 y property를 출력
  select expand(out_Address_Place.in) from ( select expand(out_Place_Address.in) from Place where "제주시 시청" in synonyms )
    : edge를 한번 더 따라가면서 출력

<update edge command>
  delete edge WorksAt from #12:3 to #13:2
  create edge WorksAt from #12:3 to #13:0

<traverse>
  traverse * from #12:0 while $depth <= 2
  traverse * from #12:0 while $depth <= 3
  traverse * from #12:5 while $depth <= 1

  traverse * from #12:0 while $depth <= 2
  == child들을 전부 가져온다
  traverse * from (select @rid from Type where type='Place' and name='장소') while $depth <= 3
  == traverse로 변경하면 $depth는 1 더해야 동일한 결과가 나온다  

<update all property>
  update MemberOf set name='소속'
  create property MemberOf.name string

<remove property>
 update MemberOf remove name

<rename edge class name>
  http://stackoverflow.com/questions/26236442/renaming-existing-edge-relationships
  alter class WorksAt name MemberOf
  update V set out_MemberOf = out_WorksAt where out_WorksAt is not null
  update V set in_MemberOf = in_WorksAt where in_WorksAt is not null
  update V remove out_WorksAt where out_WorksAt is not null
  update V remove in_WorksAt where in_WorksAt is not null

<delete vertex>
  delete vertex @rid
    : vertex와 연결된 edge 및 관련된 모든 정보들이 삭제됨

<select leaf node>
  select * from V where out('Child').size() = 0 

<remove edge and clean>
  delete edge @rid
    : 특정 id인 edge를 삭제한다. 
  update V remove in_ClassEdge where in_ClassEdge.size() = 0
  update V remove out_ClassEdge where out_ClassEdge.size() = 0
    : 삭제된 edge의 양쪽에 해당하는 record에 garbage in, out이 존재할 수 있으므로 
    : 찾아서 삭제한다. 

<expand with select edge>
  select expand(out) from Place_Category where @rid = #23:2
  select expand(in) from Place_Category where @rid = #23:2
    : Place_Category 클래스의 record id가 '#23:2'인 edge를 찾고, 그것의 시작, 끝에 해당하는 record를 보는 방법

<select with EMBEDDEDLIST STRING>
  select from Place where "서귀포시청" in synonyms
    : EMBEDDEDLIST STRING type인 synonyms에 '서귀포시청'이 있는 record를 출력

• api

• 주의사항

1. Vertex class를 하나 만들고 record간 연결을 디폴트 'E'로 하는 경우, 
   select from ClassName where out('E').size() = 0
   여기에서 out('E')가 먹히지 않는 버그가 있음
   따라서, 반드시 edge는 별도의 class로 만들어서 적용해야한다.