我想弄清楚MERGE和CREATE UNIQUE之间有什么区别.我知道这些功能:
我能够创建节点,如果不存在模式.
MERGE (n { name:"X" }) RETURN n;
这创建节点"n",其属性名称为空节点"m",关系为RELATED.
MERGE (n { name:"X" })-[:RELATED]->(m) RETURN n, m;
我无法像这样创建节点.
CREATE UNIQUE (n { name:"X" }) RETURN n;
如果存在节点"n",则创建唯一使空节点"m"和关系RELATED.
MATCH (n { name: 'X' }) CREATE UNIQUE (n)-[:RELATED]->(m) RETURN n, m;
如果存在此模式,则不会创建任何内容,只返回模式.
从我的角度来看,我看到MERGE和CREATE UNIQUE是完全相同的查询,但是使用CREATE UNIQUE,你无法在关系中创建起始节点.如果有人能解释这个问题并比较这些问题,我将不胜感激.
我在Angular应用程序中使用SignalR.当我在Angular中销毁组件时,我也想停止与集线器的连接.我使用命令:
this.hubConnection.stop();
但是我在Chrome控制台中收到错误: Websocket已关闭状态代码:1006
在Edge中:错误错误:未捕获(在承诺中):错误:由于连接被关闭而取消了调用.错误:由于连接已关闭而取消了调用.
它实际上工作,连接已经停止,但我想知道为什么我得到错误.
这就是我启动集线器的方式:
this.hubConnection = new HubConnectionBuilder()
.withUrl("/matchHub")
.build();
this.hubConnection.on("MatchUpdate", (match: Match) => {
// some magic
})
this.hubConnection
.start()
.then(() => {
this.hubConnection.invoke("SendUpdates");
});
编辑
我终于找到了这个问题.它是由Mongo改变流引起的.如果我从SendUpdates()方法中删除代码,则会触发OnDisconnected.
public class MatchHub : Hub
{
private readonly IMatchManager matchManager;
public MatchHub(IMatchManager matchManager)
{
this.matchManager = matchManager;
}
public async Task SendUpdates() {
using (var changeStream = matchManager.GetChangeStream()) {
while (changeStream.MoveNext()) {
var changeStreamDocument = changeStream.Current.FullDocument;
if (changeStreamDocument == null) {
changeStreamDocument = BsonSerializer.Deserialize<Match>(changeStream.Current.DocumentKey);
}
await Clients.Caller.SendAsync("MatchUpdate", changeStreamDocument); …我经历了整个文档,并没有找到如何设置RBF网络.我在ConsoleExmpales/Examples/Radial中找到了一些RBF示例,但看起来它不再起作用,因为在Encog中已经更改了一些方法.
到目前为止,我坚持这个:
public static double[][] XORInput = {
new[] {0.0, 0.0},
new[] {1.0, 0.0},
new[] {0.0, 1.0},
new[] {1.0, 1.0}
};
public static double[][] XORIdeal = {
new[] {0.0},
new[] {1.0},
new[] {1.0},
new[] {0.0}
};
int dimension = 8;
int numNeuronsPerDimension = 64;
double volumeNeuronWidth = 2.0 / numNeuronsPerDimension;
bool includeEdgeRBFs = true;
RBFNetwork n = new RBFNetwork(dimension, numNeuronsPerDimension, 1, RBFEnum.Gaussian);
n.SetRBFCentersAndWidthsEqualSpacing(0, 1, RBFEnum.Gaussian, volumeNeuronWidth, includeEdgeRBFs);
//n.RandomizeRBFCentersAndWidths(0, 1, RBFEnum.Gaussian);
INeuralDataSet trainingSet = new BasicNeuralDataSet(XORInput, XORIdeal);
SVDTraining train = new …我曾经在我的java maven项目中使用neo4j-community-1.9.4.我切换到2.0版并在2.0中完成了新的db.当我运行相同的Java代码时,我收到错误:
Exception in thread "main" org.neo4j.kernel.impl.storemigration.UpgradeNotAllowedByConfigurationException: Failed to start Neo4j with an older data store version. To enable automatic upgrade, please set configuration parameter "allow_store_upgrade=true"
at org.neo4j.kernel.impl.storemigration.ConfigMapUpgradeConfiguration.checkConfigurationAllowsAutomaticUpgrade(ConfigMapUpgradeConfiguration.java:39)
at org.neo4j.kernel.impl.storemigration.StoreUpgrader.attemptUpgrade(StoreUpgrader.java:64)
at org.neo4j.kernel.impl.nioneo.store.StoreFactory.tryToUpgradeStores(StoreFactory.java:104)
at org.neo4j.kernel.impl.nioneo.store.StoreFactory.newNeoStore(StoreFactory.java:86)
at org.neo4j.kernel.impl.nioneo.xa.NeoStoreXaDataSource.<init>(NeoStoreXaDataSource.java:232)
at org.neo4j.kernel.InternalAbstractGraphDatabase.create(InternalAbstractGraphDatabase.java:423)
at org.neo4j.kernel.InternalAbstractGraphDatabase.run(InternalAbstractGraphDatabase.java:226)
at org.neo4j.kernel.EmbeddedGraphDatabase.<init>(EmbeddedGraphDatabase.java:79)
at org.neo4j.graphdb.factory.GraphDatabaseFactory$1.newDatabase(GraphDatabaseFactory.java:70)
at org.neo4j.graphdb.factory.GraphDatabaseBuilder.newGraphDatabase(GraphDatabaseBuilder.java:205)
at org.neo4j.graphdb.factory.GraphDatabaseFactory.newEmbeddedDatabase(GraphDatabaseFactory.java:56)
at tools.Import.main(Import.java:32)
任何的想法？谢谢.
我有这个文件：
{
"_id" : ObjectId("5b673f525ef92ec6ef16504e"),
"events" : [
{
"name" : "Winner",
"map" : 0,
"something" : []
},
{
"name" : "Winner",
"map" : 2,
"something" : []
},
{
"name" : "DifferentName",
"map" : 2,
"something" : []
}
]
}
如果我运行以下更新：
db.getCollection('test').updateOne({
"_id": ObjectId("5b673f525ef92ec6ef16504e"),
"events.name": "Winner",
"events.map": 2
},
{$push: {
"events.$.something": {
something: "test",
}
}
})
我得到了不好的结果：
{
"_id" : ObjectId("5b673f525ef92ec6ef16504e"),
"events" : [
{
"name" : "Winner",
"map" : 0,
"something" : [
{ …我已经开始使用Kendo + ASP.NET Core.我按照本教程http://docs.telerik.com/aspnet-core/getting-started/getting-started#configuration-Add,但我收到错误:未捕获的ReferenceError:未定义kendo.
头
<link rel="stylesheet" href="/lib/bootstrap/dist/css/bootstrap.css" />
<link rel="stylesheet" href="/css/site.css" />
<link rel="stylesheet" href="/lib/kendo-ui/styles/kendo.common-nova.min.css" />
<link rel="stylesheet" href="/lib/kendo-ui/styles/kendo.nova.min.css" />
身体
<h2>Kendo UI DatePicker</h2><input id="datepicker" name="datepicker" type="text" value="" /><script>kendo.syncReady(function(){jQuery("#datepicker").kendoDatePicker({"format":"dd.MM.yyyy","footer":false});});</script>
<script src="/lib/jquery/dist/jquery.js"></script>
<script src="/lib/bootstrap/dist/js/bootstrap.js"></script>
<script src="/js/site.js?v=EWaMeWsJBYWmL2g_KkgXZQ5nPe-a3Ichp0LEgzXczKo"></script>
<script src="/lib/kendo-ui/js/kendo.all.min.js"></script>
<script src="/lib/kendo-ui/js/kendo.aspnetmvc.min.js"></script>