尽管 属性 值尚不存在，但尝试添加具有 属性 的顶点违反了唯一性约束
Trying to add a vertex with property violates uniqueness constraint despite property value is not yet present
我有一个图，其顶点带有 属性，称为 fbid，我为此创建了一个具有唯一性约束的索引。图的初始化（安装模式并添加一些初始顶点和边）使用 Java 代码发生，我添加到 Titan 库并在 gremlin shell:
中手动触发
gremlin> :> com.my.example.TestGraphFactory.loadScheme(graph)
gremlin> :> com.my.example.TestGraphFactory.loadGraph(graph)
现在，我正在尝试这样做：
gremlin> :> g.V().has('fbid', 'fbid_42')
gremlin> :> g.V().addV(label, 'user').property('fbid', 'fbid_42')
Adding this property for key [fbid] and value [fbid_42] violates a uniqueness constraint [fbid]
Display stack trace? [yN] y
org.apache.tinkerpop.gremlin.groovy.plugin.RemoteException: Adding this property for key [fbid] and value [fbid_42] violates a uniqueness constraint [fbid]
at org.apache.tinkerpop.gremlin.console.groovy.plugin.DriverRemoteAcceptor.submit(DriverRemoteAcceptor.java:116)
at org.apache.tinkerpop.gremlin.console.commands.SubmitCommand.execute(SubmitCommand.groovy:41)
at org.codehaus.groovy.tools.shell.Shell.execute(Shell.groovy:101)
at org.codehaus.groovy.tools.shell.Groovysh.super$execute(Groovysh.groovy)
at sun.reflect.GeneratedMethodAccessor14.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:324)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1207)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuperN(ScriptBytecodeAdapter.java:130)
at org.codehaus.groovy.tools.shell.Groovysh.executeCommand(Groovysh.groovy:254)
at org.codehaus.groovy.tools.shell.Groovysh.execute(Groovysh.groovy:153)
at org.codehaus.groovy.tools.shell.Shell.leftShift(Shell.groovy:119)
at org.codehaus.groovy.tools.shell.ShellRunner.work(ShellRunner.groovy:94)
at org.codehaus.groovy.tools.shell.InteractiveShellRunner.super$work(InteractiveShellRunner.groovy)
at sun.reflect.GeneratedMethodAccessor31.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:324)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1207)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuperN(ScriptBytecodeAdapter.java:130)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuper0(ScriptBytecodeAdapter.java:150)
at org.codehaus.groovy.tools.shell.InteractiveShellRunner.work(InteractiveShellRunner.groovy:123)
at org.codehaus.groovy.tools.shell.ShellRunner.run(ShellRunner.groovy:58)
at org.codehaus.groovy.tools.shell.InteractiveShellRunner.super$run(InteractiveShellRunner.groovy)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:324)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1207)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuperN(ScriptBytecodeAdapter.java:130)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuper0(ScriptBytecodeAdapter.java:150)
at org.codehaus.groovy.tools.shell.InteractiveShellRunner.run(InteractiveShellRunner.groovy:82)
at org.codehaus.groovy.vmplugin.v7.IndyInterface.selectMethod(IndyInterface.java:215)
at org.apache.tinkerpop.gremlin.console.Console.<init>(Console.groovy:144)
at org.codehaus.groovy.vmplugin.v7.IndyInterface.selectMethod(IndyInterface.java:215)
at org.apache.tinkerpop.gremlin.console.Console.main(Console.groovy:303)
我不明白这是为什么，因为这实际上是我在建立方案并用一些第一个顶点和边（其中 none 个具有这个特定 属性 值).
我应该看哪里？
原因就在这里：
gremlin> :> g.V().addV(label, 'user').property('fbid', 'fbid_42')
我太盲目了，没看到我在尝试添加新顶点之前请求获取所有顶点。因此正确的要求是
gremlin> :> g.addV(label, 'user').property('fbid', 'fbid_42')
我有一个图，其顶点带有 属性，称为 fbid，我为此创建了一个具有唯一性约束的索引。图的初始化（安装模式并添加一些初始顶点和边）使用 Java 代码发生，我添加到 Titan 库并在 gremlin shell:
gremlin> :> com.my.example.TestGraphFactory.loadScheme(graph)
gremlin> :> com.my.example.TestGraphFactory.loadGraph(graph)
现在，我正在尝试这样做：
gremlin> :> g.V().has('fbid', 'fbid_42')
gremlin> :> g.V().addV(label, 'user').property('fbid', 'fbid_42')
Adding this property for key [fbid] and value [fbid_42] violates a uniqueness constraint [fbid]
Display stack trace? [yN] y
org.apache.tinkerpop.gremlin.groovy.plugin.RemoteException: Adding this property for key [fbid] and value [fbid_42] violates a uniqueness constraint [fbid]
at org.apache.tinkerpop.gremlin.console.groovy.plugin.DriverRemoteAcceptor.submit(DriverRemoteAcceptor.java:116)
at org.apache.tinkerpop.gremlin.console.commands.SubmitCommand.execute(SubmitCommand.groovy:41)
at org.codehaus.groovy.tools.shell.Shell.execute(Shell.groovy:101)
at org.codehaus.groovy.tools.shell.Groovysh.super$execute(Groovysh.groovy)
at sun.reflect.GeneratedMethodAccessor14.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:324)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1207)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuperN(ScriptBytecodeAdapter.java:130)
at org.codehaus.groovy.tools.shell.Groovysh.executeCommand(Groovysh.groovy:254)
at org.codehaus.groovy.tools.shell.Groovysh.execute(Groovysh.groovy:153)
at org.codehaus.groovy.tools.shell.Shell.leftShift(Shell.groovy:119)
at org.codehaus.groovy.tools.shell.ShellRunner.work(ShellRunner.groovy:94)
at org.codehaus.groovy.tools.shell.InteractiveShellRunner.super$work(InteractiveShellRunner.groovy)
at sun.reflect.GeneratedMethodAccessor31.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:324)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1207)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuperN(ScriptBytecodeAdapter.java:130)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuper0(ScriptBytecodeAdapter.java:150)
at org.codehaus.groovy.tools.shell.InteractiveShellRunner.work(InteractiveShellRunner.groovy:123)
at org.codehaus.groovy.tools.shell.ShellRunner.run(ShellRunner.groovy:58)
at org.codehaus.groovy.tools.shell.InteractiveShellRunner.super$run(InteractiveShellRunner.groovy)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.codehaus.groovy.reflection.CachedMethod.invoke(CachedMethod.java:90)
at groovy.lang.MetaMethod.doMethodInvoke(MetaMethod.java:324)
at groovy.lang.MetaClassImpl.invokeMethod(MetaClassImpl.java:1207)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuperN(ScriptBytecodeAdapter.java:130)
at org.codehaus.groovy.runtime.ScriptBytecodeAdapter.invokeMethodOnSuper0(ScriptBytecodeAdapter.java:150)
at org.codehaus.groovy.tools.shell.InteractiveShellRunner.run(InteractiveShellRunner.groovy:82)
at org.codehaus.groovy.vmplugin.v7.IndyInterface.selectMethod(IndyInterface.java:215)
at org.apache.tinkerpop.gremlin.console.Console.<init>(Console.groovy:144)
at org.codehaus.groovy.vmplugin.v7.IndyInterface.selectMethod(IndyInterface.java:215)
at org.apache.tinkerpop.gremlin.console.Console.main(Console.groovy:303)
我不明白这是为什么，因为这实际上是我在建立方案并用一些第一个顶点和边（其中 none 个具有这个特定 属性 值).
我应该看哪里？
原因就在这里：
gremlin> :> g.V().addV(label, 'user').property('fbid', 'fbid_42')
我太盲目了，没看到我在尝试添加新顶点之前请求获取所有顶点。因此正确的要求是
gremlin> :> g.addV(label, 'user').property('fbid', 'fbid_42')