Question

我正在尝试获取符合以下条件的所有文档，但结果似乎不正确。

条件：发行日期与给定范围相匹配且该发行时间表有效的电影

isActive = true和releaseDate> = 2020-04-20和releaseDate <= 2020-04-21

每个文档的类型都是Movie，其中包含movieTimeline对象的列表，每个movieTimeline都有一个isActive和releaseDate属性。任何时候，单个movieTimeline都可以在文档中处于活动状态。

文档的结构-

@Document
public class Movie extends BaseDocument
{
    private String name;
    private List<MovieTimeline> movieTimelines;
...

public class MovieTimeline
{
    private Boolean isActive;
    private LocalDateTime releaseDate;
    private String description;
...

发布日期属性在Java中的类型为 LocalDateTime ，并以2020-04-20T05：00：00.000 + 00：00的格式存储在数据库中。

这是我尝试检索数据的代码-

@Repository
public interface MovieRepository extends MongoRepository<Movie,String>
{
    List<Movie> findByMovieTimelines_ReleaseDateBetweenAndMovieTimelines_IsActive(LocalDateTime from, LocalDateTime to, boolean isActive);
}

样本数据-

{
"id": "abc",
"name": "Rango",
"movieTimelines": [{
        "isActive": false,
        "releaseDate": "2020-02-10T11:30:00",
        "description": "ORIGINAL TIMELINE"
    }, {
        "isActive": true,
        "releaseDate": "2020-06-15T10:30:00",
        "description": "New Timeline created on 03/10/2020"
    }
]
}, {
    "id": "abcv",
    "name": "Fight Club",
    "movieTimelines": [{
            "isActive": false,
            "releaseDate": "2020-02-10T11:30:00",
            "description": "ORIGINAL TIMELINE"
        }, {
            "isActive": true,
            "releaseDate": "2020-05-18T10:30:00",
            "description": "New Timeline created on 02/05/2020"
        }
    ]
}, {
    "id": "asd",
    "name": "Death Note",
    "movieTimelines": [{
            "isActive": false,
            "releaseDate": "2020-03-09T10:30:00",
            "description": "ORIGINAL TIMELINE"
        }, {
            "isActive": false,
            "releaseDate": "2020-03-16T10:30:00",
            "description": "New Timeline created on 02/05/2020"
        }, {
            "isActive": false,
            "releaseDate": "2020-04-20T10:30:00",
            "description": "New Timeline created on 03/06/2020"
        }, {
            "isActive": true,
            "releaseDate": "2020-04-20T10:30:00",
            "description": "New Timeline created on 03/06/2020"
        }
    ]
}, {
    "id": "gfj",
    "name": "Andhadhun",
    "movieTimelines": [{
            "isActive": false,
            "releaseDate": "2020-04-13T10:30:00",
            "description": "ORIGINAL TIMELINE"
        }, {
            "isActive": true,
            "releaseDate": "2020-07-20T10:30:00",
            "description": "New Timeline created on 03/09/2020"
        }
    ]
}, {
    "id": "nojh",
    "name": "Evan Almighty",
    "movieTimelines": [{
            "isActive": true,
            "releaseDate": "2020-04-20T10:30:00",
            "description": "ORIGINAL TIMELINE"
        }
    ]
}

预期-

{
    "id": "asd",
    "name": "Death Note",
    "movieTimelines": [{
            "isActive": false,
            "releaseDate": "2020-03-09T10:30:00",
            "description": "ORIGINAL TIMELINE"
        }, {
            "isActive": false,
            "releaseDate": "2020-03-16T10:30:00",
            "description": "New Timeline created on 02/05/2020"
        }, {
            "isActive": false,
            "releaseDate": "2020-04-20T10:30:00",
            "description": "New Timeline created on 03/06/2020"
        }, {
            "isActive": true,
            "releaseDate": "2020-04-20T10:30:00",
            "description": "New Timeline created on 03/06/2020"
        }
    ]
},{
    "id": "nojh",
    "name": "Evan Almighty",
    "movieTimelines": [{
            "isActive": true,
            "releaseDate": "2020-04-20T10:30:00",
            "description": "ORIGINAL TIMELINE"
        }
    ]
}

MongoDB是否有任何过滤器或运算符可用于在单个查询中获取这些文档？

Answer 1

MongoDB提供$elemMatch投影运算符，该运算符应该能够满足您的条件。

尤其是，您的文档由一系列文档组成。因此，这里是另一个reference，您可以用来构造针对此类数据的查询。

这是我对您的病情和样本数据进行测试时发现的。我的查询使用的是Mongo Shell，而不是Java / Spring，因此请以所需的语言重写。

由于只想获取具有活动电影时间轴的文档，因此“ movieTimelines”中的“ isActive”属性必须为true。使用以下查询可以单独满足此条件：

db.collectionName.find({ "movieTimelines": { $elemMatch: { "isActive": true } } })

发布日期也需要在给定范围内，这意味着查询需要处理“ movieTimelines”中的“ releaseDate”属性。可以通过以下方式查询此条件：

db.collectionName.find({ "movieTimelines": { $elemMatch: { "releaseDate": { $gte: ISODate("2020-04-20T00:00:00"), $lte: ISODate("2020-04-21T00:00:00") } } } })

或

db.collectionName.find({ "movieTimelines": { $elemMatch: { "releaseDate": { $gte: ISODate("2020-04-20"), $lte: ISODate("2020-04-21") } } } })

对于上述查询，“ releaseDate”值是“ ISODate（）”对象，而不是数据库中的字符串。可以使用toDate，dateFromString等聚合器将字符串转换为ISODate对象。

即使“ releaseDate”值是字符串，如果条件中的数据类型更改为字符串，查询也将起作用。这可能不是一个好习惯。

db.collectionName.find({ "movieTimelines": { $elemMatch: { "releaseDate": { $gte: "2020-04-20", $lte: "2020-04-21" } } } })

因此，要满足这两个条件，需要将两个查询合并为一个：

db.collectionName.find({ "movieTimelines": { $elemMatch: { "isActive": true, "releaseDate": { $gte: ISODate("2020-04-20T00:00:00"), $lte: ISODate("2020-04-21T00:00:00") } } } })

我希望这能回答您的问题。

查询文档-基于对象的属性，该对象是文档内列表的一部分

1 个答案: