如何在mongodb数组文本字段中逐字符搜索? [英] How to search character by character in mongodb array text field?

问题描述

我在mongodb中的文档如下:

I have documents in mongodb are like :

[{
  "_id" : 1,
  "name" : "Himanshu",
  "tags" : ["member", "active"]
},{
  "_id" : 2,
  "name" : "Teotia",
  "tags" : ["employer", "withdrawal"]
},{ 
  "_id" : 3,
  "name" : "John",
  "tags" : ["member", "deactive"]
},{
  "_id" : 4,
  "name" : "Haris",
  "tags" : ["employer", "action"]
}]

1. 我想在这里搜索的是，如果我们有像{"tags" : ["member", "act"]}这样的过滤器数组，它会回复id的1和2，因为这里member是两个文件中的完全匹配项，而act部分匹配.
2. 如果我有类似{"tags" : ["mem"] }的过滤器，则它应该回复ID的1和3
3. 还有一种情况，如果我有类似{"tags" : ["member", "active"]}的过滤器，那么它应该只回答1.

1. What I want to search here is if we have array of filter like {"tags" : ["member", "act"]} it will reply back id's 1 and 2 because here member is full match and act partial match in two documents.
2. if I have filter like {"tags" : ["mem"] } then it should reply id's 1 and 3
3. One more case If I have filter like {"tags" : ["member", "active"]} then it should answer only 1.

推荐答案

在这里，您基本上需要两个概念.

You basically need two concepts here.

1. 将数组的每个输入字符串转换为固定在字符串开始"位置的正则表达式:

1. Convert each input string of the array into an Regular expression anchored to the "start" of the string:

在列表中使用 $all 运算符，以确保所有"匹配:

Apply the list with the $all operator to ensure "all" matches:

var filter = { "tags": [ "mem", "active" ] };

// Map with regular expressions
filter.tags = { "$all": filter.tags.map(t => new RegExpr("^" + t)) };
// makes filter to { "tags": { "$all": [ /^mem/, /^active/ ] } }

// search for results
db.collection.find(filter);

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