Mongodb string match regex

Question

I have a few mongodb docs like below:

{
    ...
    ipAddress: "1.2.3.4"
},
{
    ...
    ipAddress: "1.2.3.44,1.2.5.7"
}

The ipAddress is a string field that can contain many IPs that are separated by comma. ( "1.2.3.4,1.3.5.7,2.4.6.8" etc)

I would like to retrieve a mongo document that matches a particular IP. For which, I try the below query:

collection.findOne({
    ipAddress: new RegExp (<<the_ip>>)
});

However, while debugging my app, I realized that the above query matches and finds anything that has the_ip and not just the exact the_ip

Eg. If I have two documents that have IPs as 1.2.2.2 and 1.2.2.22 and I search for regexp 1.2.2.2, I've noticed that it always matches and returns 1.2.2.22. I feel this is expected since technically the regexp is doing it's job.

However this is not the desired outcome. How do I do a full exact IP match?

Thanks.

Answer 1

I think you need to do two things:

1. Add delimiters to the IP address
2. Escape dots in the address

For (1) do:

(^|,)<<the_ip>>(,|$)

That requires that IP is preceded by the ( ^ ) assertion at the beginning of the string or a comma and that IP is followed by a comma or the ( $ ) assertion at the end of the string.

For (2) substitute dots by \\. in the IP string.

"1.2.3.4".replace(/\./g, "\\.")

Dot in regexp means 'any character but new line', so if you don't replace it, you may accidentally match some invalid strings (eg 1a1a1a1 ).

Demo