Query Operators

In this section, we'll be exploring query operators in MongoDB. Query operators provide powerful ways to search and manipulate documents in a MongoDB collection. There are several types of query operators, including:

Comparison Operators
Logical Operators
Element Operators
Evaluation Operators
Array Operators
Bitwise Operators

Let's explore each category in more detail.

Comparison Operators

Comparison operators allow you to compare the value of a field with specified values. Some common comparison operators are:

$eq: Matches values that are equal to the specified value.
$gt: Matches values that are greater than the specified value.
$gte: Matches values that are greater than or equal to the specified value.
$lt: Matches values that are less than the specified value.
$lte: Matches values that are less than or equal to the specified value.
$ne: Matches values that are not equal to the specified value.
$in: Matches values that are in the specified array.
$nin: Matches values that are not in the specified array.

Logical Operators

Logical operators provide ways to combine multiple query conditions. Some common logical operators include:

$and: Matches documents where all the specified conditions are true.
$or: Matches documents where at least one of the specified conditions is true.
$not: Matches documents where the specified condition is not true.
$nor: Matches documents where none of the specified conditions are true.

Element Operators

Element operators target specific elements within documents, including:

$exists: Matches documents that have the specified field.
$type: Matches documents where the specified field is of the specified BSON type.

Evaluation Operators

Evaluation operators perform operations on specific fields and values, such as regular expression searches or checking the size of arrays. Some examples include:

$expr: Allows the use of aggregation expressions within query language.
$jsonSchema: Matches documents that fulfill the specified JSON Schema.
$mod: Matches documents where the specified field has a value divisible by a divisor and equal to a remainder.
$regex: Matches documents where the specified field contains a string that matches the provided regular expression pattern.
$text: Performs text search on the content of indexed fields in the documents.
$where: Matches documents that satisfy a JavaScript expression.

Array Operators

Array operators are used to query or manipulate documents that contain arrays. Some common array operators include:

$all: Matches documents where an array field contains all specified values.
$elemMatch: Matches documents where an array field contains at least one element that matches the specified conditions.
$size: Matches documents where an array field contains a specified number of elements.

Bitwise Operators

Bitwise operators allow you to perform bit manipulation on integer values. Some examples are:

$bitsAllClear: Matches documents where all bits of the specified field are clear (0) in the specified bitmask.
$bitsAllSet: Matches documents where all bits of the specified field are set (1) in the specified bitmask.
$bitsAnyClear: Matches documents where any bits of the specified field are clear (0) in the specified bitmask.
$bitsAnySet: Matches documents where any bits of the specified field are set (1) in the specified bitmask.

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