So vermeiden Sie Duplikate in arangoDB

Question

Gibt es einen "einfachen" Weg, um das Hochladen eines doppelten Dokuments (mit automatisch generiertem _key) während der Verwendung von arangoDB zu vermeiden?

Answer 1

Der Arango Weg dies zu tun ist to use a uniq hash index. Es kann jedoch nicht über das gesamte Dokument erstellt wird, nur Teile davon:

db._create("testuniq") 
[ArangoCollection 25260888467, "testuniq" (type document, status loaded)] 
arangosh [_system]> db.testuniq.ensureIndex({ type: "hash", fields:["uniqDocument", "uniqAttribute"], unique: true }) 
{ 
    "id" : "testuniq/25264886163", 
    "type" : "hash", 
    "fields" : [ 
    "uniqDocument", 
    "uniqAttribute" 
    ], 
    "selectivityEstimate" : 1, 
    "unique" : true, 
    "sparse" : false, 
    "isNewlyCreated" : true, 
    "code" : 201 
} 
arangosh [_system]> db.testuniq.save({uniqDocument: {foo: "bar"}}) 
arangosh [_system]> db.testuniq.save({uniqDocument: {foo: "bar"}}) 
JavaScript exception in file 'js/client/modules/org/arangodb/arangosh.js' at 106,13: ArangoError 1210: cannot create document, unique constraint violated 
!  throw error; 
!   ^
stacktrace: ArangoError: cannot create document, unique constraint violated 
    at Object.exports.checkRequestResult (js/client/modules/org/arangodb/arangosh.js:104:21) 
    at ArangoCollection.save.ArangoCollection.insert (js/client/modules/org/arangodb/arango-collection.js:1014:12) 
    at <shell command>:1:13 
arangosh [_system]> db.testuniq.save({uniqAttribute: "bar"}) 
arangosh [_system]> db.testuniq.save({uniqAttribute: "bar"}) 
JavaScript exception in file 'js/client/modules/org/arangodb/arangosh.js' at 106,13: ArangoError 1210: cannot create document, unique constraint violated 
!  throw error; 
!   ^
stacktrace: ArangoError: cannot create document, unique constraint violated 
    at Object.exports.checkRequestResult (js/client/modules/org/arangodb/arangosh.js:104:21) 
    at ArangoCollection.save.ArangoCollection.insert (js/client/modules/org/arangodb/arango-collection.js:1014:12) 
    at <shell command>:1:13