Question

我试图从多个数组中删除一个值，而不必发出多个Mongo命令。我的语法必须不正确，任何帮助都会受到赞赏。

当我尝试：

update = BCON_NEW("$pull", 
        "{", 
            "files.$.like", BCON_UTF8 (account_id), 
        "}",
        "{", 
            "files.$.hate", BCON_UTF8 (account_id), 
        "}",
        "{", 
            "files.$.love", BCON_UTF8 (account_id), 
        "}",
        "{", 
            "files.$.funny", BCON_UTF8 (account_id), 
        "}",
        "{", 
            "files.$.sad", BCON_UTF8 (account_id), 
        "}",
        "{", 
            "files.$.anger", BCON_UTF8 (account_id), 
        "}",
        "{", 
            "files.$.kiss", BCON_UTF8 (account_id), 
        "}"
        );

如果我将其简化为以下工作方式，则会失败：

update = BCON_NEW("$pull", 
        "{", 
            "files.$.like", BCON_UTF8 (account_id), 
        "}"
        );

Answer 1

$pull对其后的文档进行操作。见MongoDB Documentation on $pull。我以前从未见过BCON符号，所以我可能错了，但如果我理解正确，我相信你的代码创建的文档看起来像这样：

{
    $pull: { "files.$.like": BCON_UTF8 (account_id) } //Here's the end of your $pull document,
    { "files.$.hate": BCON_UTF8 (account_id) },
    { "files.$.love": BCON_UTF8 (account_id) },
    ...
},

相反，我认为你想要的东西看起来像这样（我没有测试过这个）：

update = BCON_NEW("$pull", 
    "{", 
        "files.$.like", BCON_UTF8 (account_id),  
        "files.$.hate", BCON_UTF8 (account_id), 
        "files.$.love", BCON_UTF8 (account_id), 
        "files.$.funny", BCON_UTF8 (account_id), 
        "files.$.sad", BCON_UTF8 (account_id), 
        "files.$.anger", BCON_UTF8 (account_id), 
        "files.$.kiss", BCON_UTF8 (account_id), 
    "}"
    );

在Mongo中嵌套$ pull命令

1 个答案: