如何为 Couchbase Lite 创建复杂的连接查询

Question

我正在尝试想出一个合适的连接查询来将以下文档连接在一起（人为但有用），但我什至不知道从哪里开始。

查看 official documentation 是短的，因为它似乎已经过时（IFunction 甚至不存在）。

沙发床 mobile documentation is a little more current, but I'm still struggling at making heads or tails of it. It doesn't translate 1 to 1 with the c# api.

我尝试加入的文档与此类似

    /*school.json*/
    {
        "Name": "Harvard",
        "Teachers": [
            {
                "HireDate": "1-1-2020",
                "SchoolId": "qwerty",
                "TeacherDocumentId": "Teacher::1234"
            },
            {
                "HireDate": "1-1-2019",
                "SchoolId": "zxcvb",
                "TeacherDocumentId": "Teacher::1235"
            }
        ]
    }

    /*teacher.json*/
    {
        "Id":"Teacher::1234",
        "Name": "Peggy Sue",
        "TeacherDetailDocumentId":"TeacherDetail::9876"
    }

    /*teacher.json*/
    {
        "Id":"Teacher::1235",
        "Name": "William Jackson",
        "TeacherDetailDocumentId":"TeacherDetail::9875"
    }

    /*teacherdetail.json*/
    {
        "Id":"TeacherDetail::9876",
        "CourseLoad":1
    }

    /*teacherdetail.json*/
    {
        "Id":"TeacherDetail::9875",
        "CourseLoad":3
    }

目标是投射一个复杂的 C# 对象

public class School
{
    public string Name {get;set;}
    public IEnumerable<SchoolTeacher> Teachers {get;set;}
}

public class SchoolTeacher
{
    public DateTime HireDate { get; set;}
    public string SchoolId { get; set;}
    public string TeacherDocumentId { get; set; }
    public Teacher Teacher { get; set; }
}

public class Teacher
{
    public string Id { get; set; }
    public string Name { get; set; }
    public string TeacherDetailDocumentId { get; set; }
    public TeacherDetail TeacherDetail { get; set; }
}

public class TeacherDetail
{ 
    public string Id { get; set; }
    public int CourseLoad { get; set; }

}

这类似于以下复合体 json

{
    "Name": "Harvard",
    "Teachers": [
        {
            "HireDate": "1-1-2020",
            "SchoolId": "qwerty",
            "TeacherDocumentId": "Teacher::1234",
            "Teacher": {
                "Id": "Teacher::1234",
                "Name": "Peggy Sue",
                "TeacherDetailDocumentId": "TeacherDetail::9876",
                "TeacherDetail": {
                    "Id": "TeacherDetail::9876",
                    "CourseLoad": 1
                }
            }
        },
        {
            "HireDate": "1-1-2019",
            "SchoolId": "zxcvb",
            "TeacherDocumentId": "Teacher::1235",
            "Teacher": {
                "Id": "Teacher::1235",
                "Name": "William Jackson",
                "TeacherDetailDocumentId": "TeacherDetail::9875",
                "TeacherDetail": {
                    "Id": "TeacherDetail::9875",
                    "CourseLoad": 3
                }
            }
        }
    ]
}

Answer 1

与当前的 Couchbase Lite 查询 API 一样，您将需要多个查询才能获取学校教师数组中每位教师的信息。如果您不需要一次构建整个 JSON，这可能会导致性能和内存问题，具体取决于教师的数量，您可以将查询分解为多个级别，并在需要特定数据时根据需要进行查询正在访问。

比如访问School.Teachers属性时可以先查询一个没有明细的SchoolTeacher列表。当SchoolTeacher.teacher被访问时，可以再次查询得到老师的详细信息

如何为 Couchbase Lite 创建复杂的连接查询

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