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在MongoDB中删除空文档

mongodbdocuments
3
我希望能在MongoDB中删除空文档。查询MongoDB的语句应该是什么样子的呢？我只想过滤掉不是每个字段都为空的文档，只想删除那些所有字段都等于Null的文档。
案例：
/* 1 */
{
    "_id" : ObjectId("57601e880855160fbb496f50"),
    "instemail" : [],
    "instProjekt1name" : [],
    "inststrasse" : [],
    "institutionID" : [],
    "insttelefax" : [],
    "insttelefon" : [],
    "institutionsname" : [],
    "instplz" : [],
    "insturl" : [],
    "instLand" : []
}

/* 2 */
{
    "_id" : ObjectId("57601e880855160fbb496f51"),
    "instemail" : [],
    "instProjekt1name" : [],
    "inststrasse" : [],
    "institutionID" : [],
    "insttelefax" : [],
    "insttelefon" : [],
    "institutionsname" : [],
    "instplz" : [],
    "insturl" : [],
    "instLand" : []
}

/* 3 */
{
    "_id" : ObjectId("57601e880855160fbb496f52"),
    "instemail" : [ 
        "postmaster@dfg.de"
    ],
    "instProjekt1name" : [ 
        "\n\t                                    ERA-Chemistry: Novel Pt-poor catalysts for the electrocatalytic O2 reduction based on modified, nanostructured metal oxides\n\t                                    ", 
        "\n\t                                    \"Welten\" von Mittelschichtangehörigen in zwei Satellitenstädten JABOTABEKs (Indonesien)\n\t                                    ", 
        "\n\t                                    Rätselspiele. Edition und Kommentar\n\t                                    ", 
        "\n\t                                    Analysis of the function of Presenilin in Development and Neurodegeneration in Drosophila melanogaster\n\t                                    ", 
        "\n\t                                    Estimating selection parameters and identifying loci under recent selection based on genome-wide sequence data\n\t                                    ", 
        "\n\t                                    Untersuchung polymerischer Stabilsation in kolloidalen Systemen unter Verwendung neuartiger feldtheoretischer Simulationen\n\t                                    ", 
        "\n\t                                    Entwicklung hämatopoietischer Stammzellen aus humanen ES- und iPS-Zellen\n\t                                    ", 
        "\n\t                                    Untersuchung polymerischer Stabilisation in kolloidalen Systemen unter Verwendung neuartiger feldtheoretischer Simulationen\n\t                                    "
    ],
    "inststrasse" : [ 
        "\r\n\t        \t            \t                Kennedyallee", 
        "40"
    ],
    "institutionID" : [ 
        "5000"
    ],
    "insttelefax" : [ 
        "+49 228 8852777"
    ],
    "insttelefon" : [ 
        "+49 228 8851"
    ],
    "institutionsname" : [ 
        "Deutsche Forschungsgemeinschaft"
    ],
    "instplz" : [ 
        "53175", 
        "Bonn"
    ],
    "insturl" : [ 
        "http://www.dfg.de"
    ],
    "instLand" : [ 
        "\r\n\t            \t            Deutschland\r\n\t        \t        "
    ]
}

期望的结果：

/* 3 */
{
    "_id" : ObjectId("57601e880855160fbb496f52"),
    "instemail" : [ 
        "postmaster@dfg.de"
    ],
    "instProjekt1name" : [ 
        "\n\t                                    ERA-Chemistry: Novel Pt-poor catalysts for the electrocatalytic O2 reduction based on modified, nanostructured metal oxides\n\t                                    ", 
        "\n\t                                    \"Welten\" von Mittelschichtangehörigen in zwei Satellitenstädten JABOTABEKs (Indonesien)\n\t                                    ", 
        "\n\t                                    Rätselspiele. Edition und Kommentar\n\t                                    ", 
        "\n\t                                    Analysis of the function of Presenilin in Development and Neurodegeneration in Drosophila melanogaster\n\t                                    ", 
        "\n\t                                    Estimating selection parameters and identifying loci under recent selection based on genome-wide sequence data\n\t                                    ", 
        "\n\t                                    Untersuchung polymerischer Stabilsation in kolloidalen Systemen unter Verwendung neuartiger feldtheoretischer Simulationen\n\t                                    ", 
        "\n\t                                    Entwicklung hämatopoietischer Stammzellen aus humanen ES- und iPS-Zellen\n\t                                    ", 
        "\n\t                                    Untersuchung polymerischer Stabilisation in kolloidalen Systemen unter Verwendung neuartiger feldtheoretischer Simulationen\n\t                                    "
    ],
    "inststrasse" : [ 
        "\r\n\t        \t            \t                Kennedyallee", 
        "40"
    ],
    "institutionID" : [ 
        "5000"
    ],
    "insttelefax" : [ 
        "+49 228 8852777"
    ],
    "insttelefon" : [ 
        "+49 228 8851"
    ],
    "institutionsname" : [ 
        "Deutsche Forschungsgemeinschaft"
    ],
    "instplz" : [ 
        "53175", 
        "Bonn"
    ],
    "insturl" : [ 
        "http://www.dfg.de"
    ],
    "instLand" : [ 
        "\r\n\t            \t            Deutschland\r\n\t        \t        "
    ]
}

这个句子应该怎么写？有人可以帮我吗？
在我看来，你可以通过文档的大小来找到它们！但是你需要知道你的文档类型的空文档的大小。MongoDb中的文档大小 ;)。 - shA.t
1个回答
1
网页内容由stack overflow 提供, 点击上面的
可以查看英文原文，
原文链接