The $ne Operator in MongoDB

1. the $ne Operator in MongoDB
2. Difference Between the $not and the $ne Operators

This article will discuss how the $ne operator works in MongoDB. In addition, we will enumerate its differences with the $not operator.

the $ne Operator in MongoDB

$ne is an operator in MongoDB, which stands for not equal. This compares the value of a field and checks if that is equal.

Syntax:

{field: {$ne: value}}

Suppose you have the following documents in the employee collection.

> db.employee.find().pretty()
{"_id":1,   "name":"Alice", "salary": 1500, "gender":"Female"}
{"_id":2,   "name":"Bob",   "salary": 2500, "gender":"male"}
{"_id":3,   "name":"Jhon",  "salary": 3500, "gender":"male"}
{"_id":4,   "name":"Grace", "salary": 4500, "gender":"female"}

Now, you want to see all the male employees. Then, your query should be like following:

> db.employee.find({gender:{$ne: female}}).pretty()
{"_id":2,   "name":"Bob",   "salary": 2500, "gender":"male"}
{"_id":3,   "name":"Jhon",  "salary": 3500, "gender":"male"}

Another example, say, you’ve been asked to show the female whose salary is greater than or equal to 4000. So, the query should be:

> db.employee.find({gender:{$ne: male}, salary:{$gte:4000}}).pretty()
{"_id":4,   "name":"Grace", "salary": 4500, "gender":"female"}

Difference Between the $not and the $ne Operators

You’ve seen the syntax for the $ne operator above. If you noticed, $ne only takes values as a parameter.

It simply checks whether a document has the exact value in the given field or not. In some cases, we might need a logical expression rather than a constant value; then, we will use $not.

Syntax:

{ field: { $not: { <operator-expression> } } }

Here are the similarities and differences between $ne and $not:

To know more about $ne and $not, visit the official documentation attached.