Pattern matching without using $regex operator

In MongoDB, we can do pattern matching without using the $regex operator. Simply, by using a regular expression object to specify a regular expression. Also, by using regular expression object you are allowed to use regular expression inside $ in operator.

Syntax: 

{ <field>: /pattern/<options> }

Here, // means to specify your search criteria in between these delimiters.

Example:

In the following examples, we are working with:

Database: w3wiki

Collection: employee

Documents: Six documents that contain the details of the employees in the form of field-value pairs.

• Displaying details of employee who are having the word “te” in their name by using regular expression object:

db.employee.find({Name: /te/}).pretty()

Here, we are displaying the documents of those employees whose names contain the “te” string. So, we pass a regular expression(i.e., {Name: /te/}) for the Name field in the find() method. In this regular expression, // means to specify your search criteria in between these delimiters, i.e., /te/.

MongoDB provides the functionality to search a pattern in a string during a query by writing a regular expression. A regular expression is a generalized way to match patterns with sequences of characters. MongoDB uses Perl compatible regular expressions(PCRE) version 8.42 along with UTF-8 support. In MongoDB, we can do pattern matching in two different ways:

• With $regex Operator
• Without $regex Operator