使用正则表达式的 mongoDB 更新语句 [英] mongoDB update statement using regex

问题描述

我在 mongoDB 中有以下内容:

I have the following in mongoDB:

{
    "_id" : ObjectId("552f4bf5344fbaee0f62ccef"),
    "name" : "testcase2",
    "steps" : [
        {
            "spec1" : "postPet"
        },
        {
            "spec2" : "putPet"
        },
        {
            "spec2" : "getPetsHistory"
        }
    ]
}

我想从步骤数组中提取一个元素.我只能使用以下值:testcase2"、postPet".

I want to pull an element out of the steps array. I can only use the following values: "testcase2", "postPet".

我在更新查询中使用了正则表达式，如以下链接所述:https://gist.github.com/gatesvp/1021164

I used regex in the update query as discussed in the following link: https://gist.github.com/gatesvp/1021164

我的查询是:

db.testcaseCollection.update({"name" : "testcase3"}, {$pull : {"steps" :      {$regex: 'postPet'}}})

结果是:

WriteResult({ "nMatched" : 1, "nUpserted" : 0, "nModified" : 0 })

谁能帮助我解决我做错的事情?

Can anyone help with what I am doing wrong?

推荐答案

您正在尝试根据正则表达式从数组中提取字符串.问题是你的数组由地图/对象/任何东西组成，所以你不能拉任何东西也就不足为奇了.这就是为什么您会看到 1 个 matched 和 0 个 modifying.

You are trying to pull a string from an array based on the regex. The problem is that your array consists of maps/objects/whatever, so not surprisingly you can not pull anything. This is why you see 1 matched and 0 modifies.

db.testcaseCollection.update({
  "name" : "testcase2"
}, {
   $pull : {
      steps: { spec1: {$regex: 'postPet' }}
   }
})

查看文档，了解如何使用 $pull

Take a look at documentation as to how you can use $pull

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