Question

与groupBy一起使用时，sum和populate方法遇到了一个奇怪的问题。我有一套相关的模型：用户，来源（书籍等），推荐和纪律（即学科）。

我尝试了以下水线查询：

Recommendation.find({
    where: {discipline: '5559ea07dfa9bd0499f9f799'}, 
    groupBy: ['source'], sum: ['rating']
}).exec(console.log);

这很好用，回来了：

[
    {
        "source": "5571e72ab50f0c3c49fe19f6",
        "rating": 4
    },
    {
        "source": "5571b88c51861950360fac1c",
        "rating": 12
    }
]

然后我在源代码上使用populate尝试了它，因为我希望将完整的源数据链接到每个推荐。所以我试过了：

Recommendation.find({
    where: {discipline: '5559ea07dfa9bd0499f9f799'}, 
    groupBy: ['source'], sum: ['rating']
}).populate('source').exec(console.log);

这产生了一些奇怪的东西：

[
    {
        "source": {
            "type": "book",
            "identifiers": [
                {
                    "type": "ISBN_10",
                    "identifier": "1400823226"
                },
                {
                    "type": "ISBN_13",
                    "identifier": "9781400823222"
                }
            ],
            "title": "Patterns for America",
            "subtitle": "Modernism and the Concept of Culture",
            "publisher": "Princeton University Press",
            "year": 1999,
            "language": "en",
            "categories": [
                "Literary Criticism"
            ],
            "abstract": "In recent decades, historians and social theorists have given much thought to the concept of \"culture,\" its origins in Western thought, and its usefulness for social analysis. In this book, Susan Hegeman focuses on the term's history in the United States in the first half of the twentieth century. She shows how, during this period, the term \"culture\" changed from being a technical term associated primarily with anthropology into a term of popular usage. She shows the connections between this movement of \"culture\" into the mainstream and the emergence of a distinctive \"American culture,\" with its own patterns, values, and beliefs. Hegeman points to the significant similarities between the conceptions of culture produced by anthropologists Franz Boas, Edward Sapir, Ruth Benedict, and Margaret Mead, and a diversity of other intellectuals, including Randolph Bourne, Van Wyck Brooks, Waldo Frank, and Dwight Macdonald. Hegeman reveals how relativist anthropological ideas of human culture--which stressed the distance between modern centers and \"primitive\" peripheries--came into alliance with the evaluating judgments of artists and critics. This anthropological conception provided a spatial awareness that helped develop the notion of a specifically American \"culture.\" She also shows the connections between this new view of \"culture\" and the artistic work of the period by, among others, Sherwood Anderson, Jean Toomer, Thomas Hart Benton, Nathanael West, and James Agee and depicts in a new way the richness and complexity of the modernist milieu in the United States.",
            "imageLinks": {
                "smallThumbnail": "http://bks3.books.google.de/books/content?id=OwYWU2H3me4C&printsec=frontcover&img=1&zoom=5&edge=curl&source=gbs_api",
                "thumbnail": "http://bks3.books.google.de/books/content?id=OwYWU2H3me4C&printsec=frontcover&img=1&zoom=1&edge=curl&source=gbs_api"
            },
            "createdAt": "2015-06-05T14:56:12.714Z",
            "updatedAt": "2015-06-05T14:56:12.724Z",
            "id": "5571b88c51861950360fac1c"
        },
        "rating": 4
    },
    {
        "source": {
            "_bsontype": "ObjectID",
            "id": "Uq¸Q\u0019P6\u000f¬\u001c"
        },
        "rating": 12
    }
]

正如您所看到的，不是使用完整的源属性替换源ID，而是将源作为对象添加到返回的数组中，然后添加另一个具有新的源ID引用的对象，以及总计的评级量。奇怪的是，它还只将其中一个评级值附加到它附加到结果的源对象上。

这是应该发生的事情。我不能遵循这个逻辑，感觉有点儿麻烦。在任何情况下，我想要的是在每个返回的行中包含源，以及总和。谁能解释一下这里发生了什么，如果我犯了错误呢？

难以在Sails.js中将`populate`与`groupBy`和`sum`与Waterline查询一起使用

0 个答案: