bitwise-operators.md

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Bitwise query operators

Bitwise query operators help to select documents by evaluating query conditions according to the location of bits.

Operator	Description
$bitsAllClear	Selects documents with clear bit locations (0)
$bitsAllSet	Selects documents with set bit locations (1)
$bitsAnyClear	Selects documents with at least one clear bit location (0)
$bitsAnySet	Selects documents with at least one set bit location (1)

For the examples in this section, insert the following documents into the numbers collection:

db.numbers.insertMany([
  { _id: 1, value: 23, binaryValue: '10111' },
  { _id: 2, value: 56, binaryValue: '111000' },
  { _id: 3, value: 67, binaryValue: '1000011' },
  { _id: 4, value: 102, binaryValue: '1100110' },
  { _id: 5, value: 5, binaryValue: '101' }
])

$bitsAllClear

Syntax: { <field>: { $bitsAllClear: <bitmask> } }

Use the $bitsAllClear operator to select documents where the specified bitmask locations in the query are clear (0).

:::tip The bitmask can either be a numeric or BinData value. A BinData value is a BSON type that represents a binary value. The position of the bits is read from right to left with the rightmost position being 0. :::

Example: The following query returns documents in which the value field has the second and third bit (position 1 and position 2) from the right as clear (0).

db.numbers.find({
  value: {
    $bitsAllClear: 6
  }
})

The binary representation for 6 in this query is 110. The query can also be written to show the positions of the bits to be checked:

db.numbers.find({
  value: {
    $bitsAllClear: [1, 2]
  }
})

The output:

[{ _id: 2, value: 56, binaryValue: '111000' }]

For the same query above, the bitmask can also be written as a BinData value:

db.numbers.find({
  value: {
    $bitsAllClear: BinData(0, 'Bg==')
  }
})

$bitsAllSet

Syntax: { <field>: { $bitsAllSet: <bitmask> } }

To select documents where the bitmask locations in a query are set (1), use the $bitsAllSet operator.

Example: The following query returns all the documents with positions 1 and positions 2 as set (1):

db.numbers.find({
  value: {
    $bitsAllSet: [1, 2]
  }
})

The output:

[
  { _id: 1, value: 23, binaryValue: '10111' },
  { _id: 4, value: 102, binaryValue: '1100110' }
]

See the $bitsAllClear query operator section for more usage examples.

$bitsAnyClear

Syntax: { <field>: { $bitsAnyClear: <bitmask> } }

Use the $bitsAnyClear operator to select documents where at least one of the bitmask locations in the query is clear (0).

Example: The following query returns all the documents with positions 0 and positions 2 as clear (0):

db.numbers.find({
  value: {
    $bitsAnyClear: [0, 2]
  }
})

The output:

[
  { _id: 2, value: 56, binaryValue: '111000' },
  { _id: 3, value: 67, binaryValue: '1000011' },
  { _id: 4, value: 102, binaryValue: '1100110' }
]

See the $bitsAllClear query operator section for more usage examples.

$bitsAnySet

Syntax: { <field>: { $bitsAnySet: <bitmask> } }

The $bitsAnySet operator selects documents where at least one of the bitmask locations in the query is set (1).

Example: The following query returns all the documents with positions 0 and positions 2 as set (1):

db.numbers.find({
  value: {
    $bitsAnySet: [0, 2]
  }
})

The output:

[
  { _id: 1, value: 23, binaryValue: '10111' },
  { _id: 3, value: 67, binaryValue: '1000011' },
  { _id: 4, value: 102, binaryValue: '1100110' },
  { _id: 5, value: 5, binaryValue: '101' }
]

See the $bitsAllClear query operator section for more usage examples.