MongoDB无法使用零件遍历元素 [英] MongoDB cannot use the part to traverse element

问题描述

我在数据库中有一个像这样的项目模式:

I have in my db a Project's schema like this :

Project: {
    _id: ObjectID(),
    // some data
    dashboard_group: [
        0: {
            _id: ObjectID(),
            dgr_nom: String,
            dgr_enable
        },
        // others dashboards
    ]
}

对于每个项目，只能启用一个仪表板.因此，在我在"dashboard_group"数组中添加新的仪表板(启用)之前，必须将所有其他仪表板(dgr_enable)设置为false.

For every project, it can have only one dashboard enable. So, before I add a new dashboard (enabled) in the 'dashboard_group' array, I have to set all the others dashboards (dgr_enable) on false.

为了不必检索已启用仪表板的索引，我使用标识符$ []将所有仪表板设置为false.

To not have to retrieve the index of the enabled dashboard, I use the identifier $[] to set all dashboards to false.

这是我的要求:

db.Project.update({
    _id: my_pro_id
},
{
    $set: {
        "dashboard_group.$[].dgr_enable": false
    }
}, function(err) {

});

但是Mongo向我返回此错误消息:

But Mongo return me this error message :

"cannot use the part (dashboard_group of dashboard_group.$[].dgr_enable) to traverse the element ({dashboard_group: [ { _id: ObjectId('such id'), dgr_nom: "much noun", dgr_enable: true } ]})"

我已经尝试使用标识符$，它没有返回任何错误，但是字段始终为真.

I already tried with the identifier $, it's not returning any error but the fields is allways true.

任何人都可以理解为什么此请求失败的原因吗?

Can anyone understand why this request fails ?

推荐答案

该行为通常是由更新的MongoDB安装引起的. MongoDB中内置了一个功能兼容级别"开关，该开关允许更新到较新版本，而不会以非预期的方式(不会)改变(某些)旧版本的行为. 文档，用于从v3.4升级到v3.关于该主题的6种状态:

That behaviour is often caused by an updated installation of MongoDB. There is a "feature compatibility level" switch built into MongoDB which allows for updates to a newer version that do not alter (some of) the behaviour of the old version in a non-expected (oh well) way. The documentation for upgrades from v3.4 to v3.6 states on that topic:

对于从3.4升级的部署[默认功能兼容性级别为"3.4"，直到将FeatureCompatibilityVersion设置为"3.6"为止.

For deployments upgraded from 3.4 [the default feature compatibility level is] "3.4" until you setFeatureCompatibilityVersion to "3.6".

您可以通过运行以下命令来解决此问题:

You can fix this by running the following command:

db.adminCommand( { setFeatureCompatibilityVersion: "3.6" } )

这篇关于MongoDB无法使用零件遍历元素的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！