如何强制mongo将成员存储为小写? [英] How to force mongo to store members in lowercase?

问题描述

我有一个BsonDocuments集合，例如:

I have a collection of BsonDocuments, for example:

MongoCollection<BsonDocument> products;

当我确实插入到集合中时，我希望成员名称始终为小写.阅读文档之后，ConferencePack似乎是必经之路.所以，我已经定义了这样一个:

When I do inserts into the collection, I want the member name to always be lowercase. After reading the documentation, it appears that ConventionPack is the way to go. So, I've defined one like this:

    public class LowerCaseElementNameConvention : IMemberMapConvention
{
    public void Apply(BsonMemberMap memberMap)
    {
        memberMap.SetElementName(memberMap.MemberName.ToLower());
    }

    public string Name
    {
        get { throw new NotImplementedException(); }
    }
}

在我获得集合实例之后，我就注册了这样的约定:

And right after I get my collection instance I register the convention like this:

        var pack = new ConventionPack();
        pack.Add(new LowerCaseElementNameConvention());
        ConventionRegistry.Register(
            "Product Catalog Conventions",
            pack,
            t => true);

不幸的是，这对我的收藏夹中存储的内容影响为零.我调试了它，发现Apply方法从未调用过.

Unfortunately, this has zero effect on what is stored in my collection. I debugged it and found that the Apply method is never called.

要使我的公约生效，我需要做些什么?

What do I need to do differently to get my convention to work?

推荐答案

为了使用IMemeberMapConvention，必须确保在进行映射过程之前声明约定.或选择删除现有的映射并创建新的映射.

In order to use IMemeberMapConvention, you must make sure to declare your conventions before the mapping process takes place. Or optionally drop existing mappings and create new ones.

例如，以下是应用约定的正确顺序:

For example, the following is the correct order to apply a convention:

        // first: create the conventions
        var myConventions = new ConventionPack();
        myConventions.Add(new FooConvention());

        ConventionRegistry.Register(
           "My Custom Conventions",
           myConventions,
           t => true);

        // only then apply the mapping
        BsonClassMap.RegisterClassMap<Foo>(cm =>
        {
            cm.AutoMap();
        });

        // finally save 
        collection.RemoveAll();
        collection.InsertBatch(new Foo[]
                               {
                                   new Foo() {Text = "Hello world!"},
                                   new Foo() {Text = "Hello world!"},
                                   new Foo() {Text = "Hello world!"},
                               });

以下是该示例约定的定义方式:

Here's how this sample convention was defined:

public class FooConvention : IMemberMapConvention

    private string _name = "FooConvention";

    #region Implementation of IConvention

    public string Name
    {
        get { return _name; }
        private set { _name = value; }
    }

    public void Apply(BsonMemberMap memberMap)
    {
        if (memberMap.MemberName == "Text")
        {
            memberMap.SetElementName("NotText");
        }
    }

    #endregion
}

这些是我运行此样本时得出的结果.您可能会看到Text属性最终被保存为"NotText":

These are the results that came out when I ran this sample. You could see the Text property ended up being saved as "NotText":

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