Checking if a field contains a string

I'm looking for an operator, which allows me to check, if the value of a field contains a certain string.

Something like:

db.users.findOne({$contains:{"username":"son"}})

Is that possible?

Solution 1:

You can do it with the following code.

db.users.findOne({"username" : {$regex : "son"}});

As Mongo shell support regex, that's completely possible.

db.users.findOne({"username" : /.*son.*/});

If we want the query to be case-insensitive, we can use "i" option, like shown below:

db.users.findOne({"username" : /.*son.*/i});

See: http://www.mongodb.org/display/DOCS/Advanced+Queries#AdvancedQueries-RegularExpressions

https://docs.mongodb.com/manual/reference/sql-comparison/

http://php.net/manual/en/mongo.sqltomongo.php

MySQL

SELECT * FROM users WHERE username LIKE "%Son%"

MongoDB

db.users.find({username:/Son/})

As of version 2.4, you can create a text index on the field(s) to search and use the $text operator for querying.

First, create the index:

db.users.createIndex( { "username": "text" } )

Then, to search:

db.users.find( { $text: { $search: "son" } } )

Benchmarks (~150K documents):

Notes:

A collection can have only one text index. You can use a wildcard text index if you want to search any string field, like this: db.collection.createIndex( { "$**": "text" } ).
A text index can be large. It contains one index entry for each unique post-stemmed word in each indexed field for each document inserted.
A text index will take longer to build than a normal index.
A text index does not store phrases or information about the proximity of words in the documents. As a result, phrase queries will run much more effectively when the entire collection fits in RAM.

As this is one of the first hits in the search engines, and none of the above seems to work for MongoDB 3.x, here is one regex search that does work:

db.users.find( { 'name' : { '$regex' : yourvalue, '$options' : 'i' } } )

No need to create and extra index or alike.