不设置特定参数时的ParameterNotFoundException [英] ParameterNotFoundException when not setting specific params

问题描述

我正在尝试使用Neo4jClient运行Cypher语法:

I am trying to use Neo4jClient to run the Cypher syntax:

    UNWIND {apples} AS newApple
    CREATE (a:Apple {newApple})

具有对象List<Apple> a的C#列表，其中对象可能是:

with a C# list of object List<Apple> a where the object could be:

class Apple : Fruit
{
    [JsonProperty(PropertyName = "Variety")]
    public String Variety { get; set; }
}

我不想在代码周围的不同位置散布对象变量规范.

I do not want to spread out object variable specs in different places around the code.

但是跑步

            graphClient.Cypher
                .Unwind(a, "newApple")
                .Create("(a: Apple {newApple})")
                .ExecuteWithoutResults()

抛出:

Neo4jClient.NeoException:'ParameterNotFoundException:需要一个名为newApple的参数'

Neo4jClient.NeoException: 'ParameterNotFoundException: Expected a parameter named newApple'

将Create行更改为

            .Create("(a: Apple {Id: newApple.Id})")

似乎可以正常工作，因此找到了预期的参数newApple.这里的问题是，如果更改类的属性，则必须更改密码查询字符串中的直接依赖关系.

seems to work though, so the expected parameter newApple is found. The problem here is that if I change the properties of the class, I have to change the direct dependency in the cypher query string.

1. 这是为什么?我希望在两种情况下都能找到Unwind中指定的标识符.
2. 有什么变通办法可以保留通用代码吗?我的目标是能够发送任何POCO对象以自动与新节点类型参数匹配.

1. Why is this? I would expect the identifier specified in Unwind would be found in both cases.
2. Any workaround so that I can keep the generalized code? I aim to be able to send in any POCO object to automatically match with neo node type params.

推荐答案

因为newApple不再是参数，而是变量，而您使用的语法只能与外部参数一起应用.

Because the newApple is no longer a parameter, but a variable, whereas the syntax used by you can only be applied with external parameters.

对于变量可以这样使用:

For variables can be used this way:

WITH [{id: 1, name: 'appe1'}, {id: 2, name: 'apple2'}] as apples
UNWIND apples as newApple
CREATE (a:Apple) SET a = newApple
RETURN a

这篇关于不设置特定参数时的ParameterNotFoundException的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！