Bitwise query operators

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

OperatorDescription
$bitsAllClearSelects documents with clear bit locations (0)
$bitsAllSetSelects documents with set bit locations (1)
$bitsAnyClearSelects documents with at least one clear bit location (0)
$bitsAnySetSelects documents with at least one set bit location (1)

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

  1. db.numbers.insertMany([
  2.   { _id: 1, value: 23, binaryValue: '10111' },
  3.   { _id: 2, value: 56, binaryValue: '111000' },
  4.   { _id: 3, value: 67, binaryValue: '1000011' },
  5.   { _id: 4, value: 102, binaryValue: '1100110' },
  6.   { _id: 5, value: 5, binaryValue: '101' }
  7. ])

$bitsAllClear

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

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

Bitwise query operators - 图1tip

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).

  1. db.numbers.find({
  2.   value: {
  3.     $bitsAllClear: 6
  4.   }
  5. })

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:

  1. db.numbers.find({
  2.   value: {
  3.     $bitsAllClear: [1, 2]
  4.   }
  5. })

The output:

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

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

  1. db.numbers.find({
  2.   value: {
  3.     $bitsAllClear: BinData(0, 'Bg==')
  4.   }
  5. })

$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):

  1. db.numbers.find({
  2.   value: {
  3.     $bitsAllSet: [1, 2]
  4.   }
  5. })

The output:

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

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):

  1. db.numbers.find({
  2.   value: {
  3.     $bitsAnyClear: [0, 2]
  4.   }
  5. })

The output:

  1. [
  2.   { _id: 2, value: 56, binaryValue: '111000' },
  3.   { _id: 3, value: 67, binaryValue: '1000011' },
  4.   { _id: 4, value: 102, binaryValue: '1100110' }
  5. ]

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):

  1. db.numbers.find({
  2.   value: {
  3.     $bitsAnySet: [0, 2]
  4.   }
  5. })

The output:

  1. [
  2.   { _id: 1, value: 23, binaryValue: '10111' },
  3.   { _id: 3, value: 67, binaryValue: '1000011' },
  4.   { _id: 4, value: 102, binaryValue: '1100110' },
  5.   { _id: 5, value: 5, binaryValue: '101' }
  6. ]

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