MongoDB在多个字段上的唯一索引 [英] MongoDB Unique index on multiple field

问题描述

我正在使用MongoDb数据库，我需要使多个字段唯一.我需要MongoDb检查多个字段的 combination 是否唯一.让我们展示一个我需要的例子:

I'm using a MongoDb database and I need to make multiple fields unique. What I need is for MongoDb to check if the combination of the multiple fields are unique. Let's show an example of what I need:

如果在添加索引后按以下顺序在数据库中添加以下内容:
{"name":"paul"，"age":"21"}
{"name":"goerge"，"age":"21"}
{名称":保罗"，年龄":"44"}
{"name":"paul"，"age":"21"}

If I add the following in this order in the database after adding the indexes:
{"name":"paul", "age":"21"}
{"name":"goerge", "age":"21"}
{"name":"paul", "age":"44"}
{"name":"paul", "age":"21"}

在下面的示例中，将不被接受的 only 是最后一个.

In the following example, the only one who would not be accepted would be the last one.

我尝试了以下唯一的复合索引，但它不起作用.在前面的示例中，它将仅保留第一个字段，因为它检查每个字段是否唯一:

I've tried the following unique compound index and it doesn't work. In the preceding example, it would only keep the first one as it checks if every field is unique:

db.test.createIndex({"name":1，"age":1}，{unique:true})

我也尝试过，同样的问题:

I also tried, same problem:

db.test.createIndex({"name":1}，{unique:true})
db.test.createIndex({"age":1}，{unique:true})

我搜索了几个小时，却找不到任何可以使我做到这一点的东西.

I searched for hours and couldn't find anything that would enable me to do that.

有人知道吗?

推荐答案

您无法创建唯一的索引，因为您已经有了&年龄不是唯一的！检查保罗21岁如果您修复该值.创建索引的最佳方法就是这种方法db.test.createIndex({"name":1，"age":1}，{unique:true})

You aren't able to create that index unique because you 've got the name & age not unique! Check Paul 21 years olds If you fix that value. The best way to create the index is this one db.test.createIndex({"name":1, "age":1}, {unique:true})

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