$bitsAnySetNew in version 3.2.
$bitsAnySetmatches documents where any of the bit positions given by the query are set (i.e.1) infield.{ <field>: { $bitsAnySet: <numeric bitmask> } }{ <field>: { $bitsAnySet: <BinDatabitmask> } }{ <field>: { $bitsAnySet: [ <position1>, <position2>, ... ] } }The
fieldvalue must be either numeric or a BinData instance. Otherwise,$bitsAnySetwill not match the current document.- Numeric Bitmask
- You can provide a numeric bitmask to be matched against the operand field.
It must be representable as a non-negative 32-bit signed integer. Otherwise,
$bitsAnySetwill return an error. - BinData Bitmask
- You can also use an arbitrarily large BinData instance as a bitmask.
- Position List
- If querying a list of bit positions, each
<position>must be a non-negative integer. Bit positions start at0from the least significant bit. For example, the decimal number254would have the following bit positions:
Bit Value11111110Position
7
6
5
4
3
2
1
0
Behavior
Indexes
Queries cannot use indexes for the $bitsAnySet portion of a
query, although the other portions of a query can use indexes, if
applicable.
Floating Point Values
$bitsAnySet will not match numerical values that cannot be represented as
a signed 64-bit integer. This can be the case if a value is either too large
or too small to fit in a signed 64-bit integer, or if it has a fractional
component.
Sign Extension
Numbers are sign extended. For example, $bitsAnySet considers bit position 200
to be set for the negative number -5, but bit position 200 to be clear
for the positive number +5.
In contrast, BinData instances are zero-extended. For example, given the following document:
db.collection.save({ x: BinData(0, "ww=="), binaryValueofA: "11000011" })
$bitsAnySet will consider all bits outside of x to be clear.
Examples
The following examples will use a collection with the following documents:
db.collection.save({ _id: 1, a: 54, binaryValueofA: "00110110" }) db.collection.save({ _id: 2, a: 20, binaryValueofA: "00010100" }) db.collection.save({ _id: 3, a: 20.0, binaryValueofA: "00010100" }) db.collection.save({ _id: 4, a: BinData(0, "Zg=="), binaryValueofA: "01100110" })
Bit Position Array
The following query uses the $bitsAnySet operator to test
whether field a has either bit position 1 or bit position 5 set,
where the least significant bit is position 0.
db.collection.find( { a: { $bitsAnySet: [ 1, 5 ] } } )
The query matches the following documents:
{ "_id" : 1, "a" : 54, "binaryValueofA" : "00110110" } { "_id" : 4, "a" : BinData(0,"Zg=="), "binaryValueofA" : "01100110" }
Integer Bitmask
The following query uses the $bitsAnySet operator to test
whether field a has any bits set at positions 0, 1, and 5
(the binary representation of the bitmask 35 is 00100011).
db.collection.find( { a: { $bitsAnySet: 35 } } )
The query matches the following documents:
{ "_id" : 1, "a" : 54, "binaryValueofA" : "00110110" } { "_id" : 4, "a" : BinData(0,"Zg=="), "binaryValueofA" : "01100110" }
BinData Bitmask
The following query uses the $bitsAnySet operator to test
whether field a has any bits set at positions 4, and 5
(the binary representation of BinData(0, "MA==") is 00110000).
db.collection.find( { a: { $bitsAnySet: BinData(0, "MA==") } } )
The query matches the following documents:
{ "_id" : 1, "a" : 54, "binaryValueofA" : "00110110" } { "_id" : 2, "a" : 20, "binaryValueofA" : "00010100" } { "_id" : 3, "a" : 20.0, "binaryValueofA" : "00010100" } { "_id" : 4, "a" : BinData(0,"Zg=="), "binaryValueofA" : "01100110" }