Querying Firestore documents by nested key-value in an array field using Python

该 issue 未指定任何仓库文件或测试。首先结合 Python FieldFilter API，检查 Firestore 对 array-contains 和嵌套字段的查询行为；完成的标准是确定是否支持此谓词，并记录适当的查询方式或该限制。

Is your feature request related to a problem? Please describe.
I'm working with Firestore in Python and have a data query challenge I'm hoping to get some advice on.

My documents in Firestore are structured as follows:

{
  "key1": "value1",
  "key2": {
    "subKey1": [
      {
        "arrayKey1": "arrayValue1",
        "arrayKey2": "arrayValue2"
      },
      {
        "arrayKey3": "arrayValue3",
        "arrayKey4": "arrayValue4"
      }
    ],
    "subKey2": "subValue2"
  }
}

My goal is to query documents where the value of arrayKey1 within the subKey1 array matches a specific value (for example, target_arrayValue1), regardless of the arrayKey2 in the same dictionary.

Here's an example of what my query currently looks like:

docs = query.where(
    filter=FieldFilter(
        "key2.subKey1",
        "array_contains",
        {
            "arrayKey1": "target_arrayValue1",
            "arrayKey2": "arrayValue2"
        }
    )
).stream()

This approach, however, requires a full match of the dictionary, which is not ideal.

Describe the solution you'd like
My “ideal” code would do something like this:

docs = query.where(
    filter=FieldFilter(
        "key2.subKey1.0.arrayKey1", 
        "==",
        "target_arrayValue1"
    )
).stream()

Is there an appropriate way to structure my query to achieve this? Any insights or examples would be greatly appreciated! Thanks in advance.