MongoDB Extended JSON (v1)
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Important
Disambiguation
The following page discusses MongoDB Extended JSON v1 (Legacy extended JSON). For discussion on MongoDB Extended JSON v2, see MongoDB Extended JSON (v2).
For mongo
shell wrapper methods for types, see
Data Types in the mongo
Shell.
JSON can only represent a subset of the types supported by BSON. To preserve type information, MongoDB adds the following extensions to the JSON format:
Strict mode. Strict mode representations of BSON types conform to the JSON RFC. Any JSON parser can parse these strict mode representations as key/value pairs; however, only the MongoDB internal JSON parser recognizes the type information conveyed by the format.
mongo
Shell mode. The MongoDB internal JSON parser and themongo
shell can parse this mode.
The representation used for the various data types depends on the context in which the JSON is parsed.
MongoDB Extended JSON v1 and MongoDB Drivers
The following drivers use the Extended JSON v1.0 (Legacy)
C#
Ruby
For the other drivers, refer to MongoDB Extended JSON (v2).
Parsers and Supported Format
Input in Strict Mode
The following can parse representations in strict mode with recognition of the type information.
mongoimport
version 4.0 and earlier--query
option of various MongoDB tools
Other JSON parsers, including mongo
shell, can parse
strict mode representations as key/value pairs, but without
recognition of the type information.
Input in mongo
Shell Mode
The following can parse representations in mongo
shell mode with
recognition of the type information.
mongoimport
version 4.0 and earlier--query
option of various MongoDB toolsmongo
shell
Output in Strict mode
Before version 4.2, mongoexport
outputs data in Strict mode
of MongoDB Extended JSON v1.
Output in mongo
Shell Mode
Before version 4.2, bsondump
outputs in mongo
Shell
mode.
BSON Data Types and Associated Representations
The following presents the BSON data types and the associated
representations in Strict mode and mongo
Shell mode.
Binary
data_binary
- Strict Mode
mongo
Shell Mode{ "$binary": "<bindata>", "$type": "<t>" } BinData ( <t>, <bindata> )
Where the values are as follows:
<bindata>
is the base64 representation of a binary string.<t>
is a representation of a single byte indicating the data type. In Strict mode it is a hexadecimal string, and in Shell mode it is an integer. See the extended bson documentation. http://bsonspec.org/spec.html
Date
data_date
- Strict Mode
mongo
Shell Mode{ "$date": "<date>" } new Date ( <date> ) In Strict mode,
<date>
is an ISO-8601 date format with a mandatory time zone field following the templateYYYY-MM-DDTHH:mm:ss.mmm<+/-Offset>
.In Shell mode,
<date>
is the JSON representation of a 64-bit signed integer giving the number of milliseconds since epoch UTC.
Timestamp
data_timestamp
- Strict Mode
mongo
Shell Mode{ "$timestamp": { "t": <t>, "i": <i> } } Timestamp( <t>, <i> )
Where the values are as follows:
<t>
is the JSON representation of a 32-bit unsigned integer for seconds since epoch.<i>
is a 32-bit unsigned integer for the increment.
Regular Expression
data_regex
- Strict Mode
mongo
Shell Mode{ "$regex": "<sRegex>", "$options": "<sOptions>" } /<jRegex>/<jOptions>
Where the values are as follows:
<sRegex>
is a string of valid JSON characters.<jRegex>
is a string that may contain valid JSON characters and unescaped double quote ("
) characters, but may not contain unescaped forward slash (/
) characters.<sOptions>
is a string containing the regex options represented by the letters of the alphabet.<jOptions>
is a string that may contain only the characters 'g', 'i', 'm' and 's' (added in v1.9). Because theJavaScript
andmongo Shell
representations support a limited range of options, any nonconforming options will be dropped when converting to this representation.
OID
data_oid
- Strict Mode
mongo
Shell Mode{ "$oid": "<id>" } ObjectId( "<id>" )
Where the values are as follows:
<id>
is a 24-character hexadecimal string.
DB Reference
data_ref
- Strict Mode
mongo
Shell Mode{ "$ref": "<name>", "$id": "<id>" } DBRef("<name>", "<id>")
Where the values are as follows:
<name>
is a string of valid JSON characters.<id>
is any valid extended JSON type.
Undefined Type
data_undefined
- Strict Mode
mongo
Shell Mode{ "$undefined": true } undefined The representation for the JavaScript/BSON undefined type.
You cannot use
undefined
in query documents. Consider the following document inserted into thepeople
collection:db.people.insert( { name : "Sally", age : undefined } ) The following queries return an error:
db.people.find( { age : undefined } ) db.people.find( { age : { $gte : undefined } } ) However, you can query for undefined values using
$type
, as in:db.people.find( { age : { $type : 6 } } ) This query returns all documents for which the
age
field has valueundefined
.
MinKey
data_minkey
- Strict Mode
mongo
Shell Mode{ "$minKey": 1 } MinKey The representation of the MinKey BSON data type that compares lower than all other types. See Comparison/Sort Order for more information on comparison order for BSON types.
MaxKey
data_maxkey
- Strict Mode
mongo
Shell Mode{ "$maxKey": 1 } MaxKey The representation of the MaxKey BSON data type that compares higher than all other types. See Comparison/Sort Order for more information on comparison order for BSON types.
NumberLong
data_numberlong
- Strict Mode
mongo
Shell Mode{ "$numberLong": "<number>" } NumberLong( "<number>" ) NumberLong
is a 64 bit signed integer. You must include quotation marks or it will be interpreted as a floating point number, resulting in a loss of accuracy.For example, the following commands insert
9223372036854775807
as aNumberLong
with and without quotation marks around the integer value:db.json.insert( { longQuoted : NumberLong("9223372036854775807") } ) db.json.insert( { longUnQuoted : NumberLong(9223372036854775807) } ) When you retrieve the documents, the value of
longUnQuoted
has changed, whilelongQuoted
retains its accuracy:db.json.find() { "_id" : ObjectId("54ee1f2d33335326d70987df"), "longQuoted" : NumberLong("9223372036854775807") } { "_id" : ObjectId("54ee1f7433335326d70987e0"), "longUnQuoted" : NumberLong("-9223372036854775808") }
NumberDecimal
New in version 3.4.
data_numberdecimal
- Strict Mode
mongo
Shell Mode{ "$numberDecimal": "<number>" } NumberDecimal( "<number>" ) NumberDecimal
is a high-precision decimal. You must include quotation marks, or the input number will be treated as a double, resulting in data loss.For example, the following commands insert
123.40
as aNumberDecimal
with and without quotation marks around the value:db.json.insert( { decimalQuoted : NumberDecimal("123.40") } ) db.json.insert( { decimalUnQuoted : NumberDecimal(123.40) } ) When you retrieve the documents, the value of
decimalUnQuoted
has changed, whiledecimalQuoted
retains its specified precision:db.json.find() { "_id" : ObjectId("596f88b7b613bb04f80a1ea9"), "decimalQuoted" : NumberDecimal("123.40") } { "_id" : ObjectId("596f88c9b613bb04f80a1eaa"), "decimalUnQuoted" : NumberDecimal("123.400000000000") }