ArangoDB is a multi-model database with the ability to store data as graphs, documents, and key-value.
Took material from a free course on Udemy and Outline of the course
It is worth paying attention to the training center and docks
You can work on the HTTP API , front , terminal and python library
Concept
ArangoDB stores objects in json documents with support for key reversal, for which a special _key field is responsible .
There are two types of collections:
Standard. Json document store, special fields _key, _rev, _id . key can be set yourself. The last two are created automatically.
_key is the key of the object in the collection. IMPORTANT: case sensitive
_rev - used for internal algorithms
_id - used to communicate with other collections. It has the format {collection name} / _ key
Edge. Special collections that store the objects of communication between the objects of standard collections. I have two additional fields _ to, _from , which store the _id of objects, which the edge object connects
CRUD
AQL.
. , _key .
:
INSERT {key: value} INTO collection [RETURN NEW]
RETURN NEW
:
RETURN DOCUMENT(_id) – _id RETURN DOCUMENT(collection_name, [_key, ...]) –
:
UPDATE {_key: "value"} WITH {newVal: 1234} IN collection
:
REMOVE {_key: "value"} IN collection
FOR
: FOR variableName IN expression
Update :
FOR doc in ["key1", "key2"]:
UPDATE doc WITH {newVal: 1234} IN collection
. _key, _id, _to _from .
7 :
Primary – _key _id
Edge – _from _to
Hash –
Skiplist
Persistent
Geo
Fulltext
Selectivity,
: FILTER condition
.
, :
FOR flight IN flights
FILTER flight.type == "VIP"
RETURN flight
.
.
, .
FOR airport IN airports
FILTER airport.city == "Dallas"
FOR flight in flights
FILTER flight._to == airport._id
RETURN {"airport": airport.name, "flight": flight.FlightNum}
:
COLLECT variableName = expression options
, :
FOR airport IN airports COLLECT state = airport.state RETURN state
FOR airport IN airports
COLLECT state = airport.state WITH COUNT INTO total
SORT total DESC
RETURN {"state": state, "total":total}
(edge collections). _id, .
edge _to _from, _id , . json, , .
:
FOR vertex, edge, path IN 1..1 OUTBOUND _id GRAPH edge_collection RETURN path
FOR vertex, edge, path IN 1..1 OUTBOUND _id edge_collection RETURN path – , GRAPH. edge
vertex – ,
edge –
path – :
IN , min..max
OUTBOUND/INBOUND/ANY . _from, _to .
_id id .
GRAPH edge ,
, - :
FOR airport in airports
FILTER airport.city == "San Francisco"
FOR v, e, p IN 1..1 OUTBOUND airport flights
FILTER v._id == "airports/KOA"
RETURN p
- :
FOR airport in airports
FILTER airport.city == "San Francisco"
FOR v, e, p IN 2..3 OUTBOUND airport flights
FILTER v._id == "airports/KOA"
RETURN p
, .
ArangoSearch, .
, ,
ArangoSearch : .
– analyzers, views links
Analyzers , . . .
Views , /
Links views . .
Integration engine - data provision layer.
Search is a preprocessor, works on views, can only see indexed fields, that is, those that we described in links.
Rank allows you to get the weight of the results, according to the search request. We can also set our own weights for the search parts.
An example of finding the word "ninja" in a movie description:
FOR doc in view
SEARCH ANALYZER(d.description == "ninja", "text_en")
RETURN doc