嵌套Avro模式 [英] Nesting Avro schemas

问题描述

根据此问题，有关嵌套Avro模式，嵌套记录架构的正确方法如下:

According to this question on nesting Avro schemas, the right way to nest a record schema is as follows:

{
    "name": "person",
    "type": "record",
    "fields": [
        {"name": "firstname", "type": "string"},
        {"name": "lastname", "type": "string"},
        {
            "name": "address",
            "type": {
                        "type" : "record",
                        "name" : "AddressUSRecord",
                        "fields" : [
                            {"name": "streetaddress", "type": "string"},
                            {"name": "city", "type": "string"}
                        ]
                    },
        }
    ]
}

我不喜欢为字段指定名称address，而不必为字段的架构指定其他名称(AddressUSRecord).我可以给字段和架构起一个相同的名称address吗?

I don't like giving the field the name address and having to give a different name (AddressUSRecord) to the field's schema. Can I give the field and schema the same name, address?

如果我想在多个其他架构中使用AddressUSRecord架构，而不仅仅是person怎么办?如果我想在其他架构中使用AddressUSRecord，比如说business，是否还需要命名呢?

What if I want to use the AddressUSRecord schema in multiple other schemas, not just person? If I want to use AddressUSRecord in another schema, let's say business, do I have to name it something else?

理想情况下，我想在单独的架构中定义AddressUSRecord，然后让address的类型引用AddressUSRecord.但是，尚不清楚Avro 1.8.1是否支持此开箱即用的功能.此 2014年文章显示，需要处理子方案与自定义代码.在Avro 1.8.1中定义可重用架构的最佳方法是什么?

Ideally, I'd like to define AddressUSRecord in a separate schema, then let the type of address reference AddressUSRecord. However, it's not clear that Avro 1.8.1 supports this out-of-the-box. This 2014 article shows that sub-schemas need to be handled with custom code. What the best way to define reusable schemas in Avro 1.8.1?

注意:我想要一个与Confluent Inc.的Schema Registry一起使用的解决方案.有一个 Google网上论坛线程，似乎暗示了该架构注册表不适用于架构引用.

Note: I'd like a solution that works with Confluent Inc.'s Schema Registry. There's a Google Groups thread that seems to suggest that Schema Registry does not play nice with schema references.

推荐答案

我可以为字段和模式指定相同的名称，地址吗?

Can I give the field and schema the same name, address?

是的，您可以使用与字段名称相同的名称来命名记录.

Yes, you can name the record with the same name as the field name.

如果我想在多个其他模式(而不仅仅是个人)中使用AddressUSRecord模式，该怎么办?

What if I want to use the AddressUSRecord schema in multiple other schemas, not just person?

您可以使用以下两种技术使用多个模式:avro模式解析器客户端(JVM和其他客户端)允许您通常通过names参数来指定多个模式(Java Schema$Parser/parse方法允许多个模式参数).

You can use multiple schemas using a couple of techniques: the avro schema parser clients (JVM and others) allow you to specify multiple schemas, usually through the names parameter (the Java Schema$Parser/parse method allows multiple schema String arguments).

然后，您可以将依赖的模式指定为命名类型:

You can then specify dependant Schemas as a named type:

{
  "type": "record",
  "name": "Address",
  "fields": [
    {
      "name": "streetaddress",
      "type": "string"
    },
    {
      "name": "city",
      "type": "string"
    }
  ]
}

并在父架构之前通过解析器运行它:

And run this through the parser before the parent schema:

{
  "name": "person",
  "type": "record",
  "fields": [
    {
      "name": "firstname",
      "type": "string"
    },
    {
      "name": "lastname",
      "type": "string"
    },
    {
      "name": "address",
      "type": "Address"
    }
  ]
}

顺便说一句，这使您可以从单独的文件中进行解析.

Incidentally, this allows you to parse from separate files.

或者，您也可以解析以相同方式引用架构的单个Union架构:

Alternatively, you can also parse a single Union schema that references schemas in the same way:

[
  {
    "type": "record",
    "name": "Address",
    "fields": [
      {
        "name": "streetaddress",
        "type": "string"
      },
      {
        "name": "city",
        "type": "string"
      }
    ]
  },
  {
    "type": "record",
    "name": "person",
    "fields": [
      {
        "name": "firstname",
        "type": "string"
      },
      {
        "name": "lastname",
        "type": "string"
      },
      {
        "name": "address",
        "type": "Address"
      }
    ]
  }
]

我想要一个与Confluent Inc.的Schema Registry一起使用的解决方案.

I'd like a solution that works with Confluent Inc.'s Schema Registry.

模式注册表不支持单独解析模式，但是它支持后者解析为联合类型的示例.

The schema registry does not support parsing schemas separately, but it does support the latter example of parsing into a union type.

这篇关于嵌套Avro模式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！