MongoDB Extended JSON (v2)
Important
Disambiguation
The following page discusses MongoDB Extended JSON v2. For discussion on the Legacy MongoDB Extended JSON v1, see MongoDB Extended JSON (v1).
For supported data types in mongosh
, see
mongosh Data Types.
JSON can only directly represent a subset of the types supported by BSON. To preserve type information, MongoDB adds the following extensions to the JSON format.
- Canonical Mode
- A string format that emphasizes type preservation at the expense of readability and interoperability. That is, conversion from canonical to BSON will generally preserve type information except in certain specific cases.
- Relaxed Mode
- A string format that emphasizes readability and interoperability at the expense of type preservation. That is, conversion from relaxed format to BSON can lose type information.
Both formats conform to the JSON RFC and can be parsed by the various MongoDB drivers and tools.
MongoDB Extended JSON v2 Usage
Drivers
The following drivers use the Extended JSON v2.0
|
|
|
For C# and Ruby that use Legacy MongoDB Extended JSON v1, refer to MongoDB Extended JSON (v1).
Extended JSON Methods
MongoDB provides the following methods for Extended JSON:
Method | Description | |
serialize | Serializes a BSON object and returns the data in Extended JSON format.
| |
deserialize | Converts a serialized document to field and value pairs. The values have BSON types.
| |
stringify | Converts the element and type pairs in a deserialized object to strings.
| |
parse | Converts strings into element and type pairs.
|
For usage examples, see Extended JSON Object Conversions below.
For additional details, see the documentation for:
MongoDB Database Tools
Starting in version 4.2:
Binary | Changes |
---|---|
Uses Extended JSON v2.0 (Canonical
mode) format. | |
Use Extended JSON v2.0 (Canonical mode) format for the
metadata. Requires TipIn general, use corresponding versions of
| |
Creates output data in Extended JSON v2.0 (Relaxed mode) by
default. Creates output data in Extended JSON v2.0 (Canonical mode) if
used with --jsonFormat . | |
Expects import data to be in Extended JSON v2.0 (either
Relaxed or Canonical mode) by default. Can recognize data that is in Extended JSON v1.0 format if the option
--legacy is specified.TipIn general, the versions of |
BSON Data Types and Associated Representations
The following presents some common BSON data types and the associated representations in Canonical and Relaxed.
The complete list is here.
Canonical | Relaxed | ||
---|---|---|---|
|
|
Where the array elements are as follows:
<elements>
Array elements use Extended JSON.
To specify an empty array, omit the content
[ ]
.
Canonical | Relaxed | |||||||
---|---|---|---|---|---|---|---|---|
|
|
Where the values are as follows:
"<payload>"
Base64 encoded (with padding as "=") payload string.
"<t>"
A one- or two-character hex string that corresponds to a BSON binary subtype. See the extended bson documentation http://bsonspec.org/spec.html for subtypes available.
For dates between years 1970 and 9999, inclusive:
Canonical | Relaxed | ||
---|---|---|---|
|
|
For dates before year 1970 or after year 9999:
Canonical | Relaxed | ||
---|---|---|---|
|
|
Where the values are as follows:
"<millis>"
A 64-bit signed integer as string. The value represents milliseconds relative to the epoch.
"<ISO-8601 Date/Time Format>"
A date in ISO-8601 Internet Date/Time Format as string.
The date/time has a maximum time precision of milliseconds:
Fractional seconds have exactly 3 decimal places if the fractional part is non-zero.
Otherwise, fractional seconds SHOULD be omitted if zero.
Canonical | Relaxed | ||
---|---|---|---|
|
|
Where the values are as follows:
"<number>"
A high-precision decimal as a string.
Canonical | Relaxed | ||
---|---|---|---|
|
|
Where the document contents are as follows:
<content>
Name:value pairs that use Extended JSON.
To specify an empty document, omit the content
{ }
.
For finite numbers:
Canonical | Relaxed | ||
---|---|---|---|
|
|
For infinite numbers or NAN:
Canonical | Relaxed | ||
---|---|---|---|
|
|
Where the values are as follows:
"<decimal string>"
A 64-bit signed floating point as a string.
<non-integer number>
A non-integer number. Integer numbers are parsed as an integer instead of a double.
Canonical | Relaxed | ||
---|---|---|---|
|
|
Where the values are as follows:
"<number>"
A 64-bit signed integer as string.
<integer>
A 64-bit signed integer.
Canonical | Relaxed | ||
---|---|---|---|
|
|
Where the values are as follows:
"<number>"
A 32-bit signed integer as a string.
<integer>
A 32-bit signed integer.
Canonical | Relaxed | ||
---|---|---|---|
|
|
The MaxKey BSON data type compares higher than all other types. See Comparison/Sort Order for more information on comparison order for BSON types.
Canonical | Relaxed | ||
---|---|---|---|
|
|
The MinKey BSON data type compares lower than all other types. See Comparison/Sort Order for more information on comparison order for BSON types.
Canonical | Relaxed | ||
---|---|---|---|
|
|
Where the values are as follows:
"<ObjectId bytes>"
A 24-character, big-endian hexadecimal string that represents the ObjectId bytes.
Canonical | Relaxed | |||||||
---|---|---|---|---|---|---|---|---|
|
|
Where the values are as follows:
"<regexPattern>"
A string that corresponds to the regular expression pattern. The string can contain valid JSON characters and unescaped double quote (
"
) characters, but may not contain unescaped forward slash (/
) characters.
"<options>"
A string that specifies BSON regular expression options. You must specify the options in alphabetical order. For information on the supported options, see
$options
.
Canonical | Relaxed | ||
---|---|---|---|
|
|
Where the values are as follows:
<t>
A positive integer for the seconds since epoch.
<i>
A positive integer for the increment.
Examples
The following examples illustrate Extended JSON usage.
Type Representations
Example Field Name | Canonical Format | Relaxed Format |
---|---|---|
"_id:" | {"$oid":"5d505646cf6d4fe581014ab2"} | {"$oid":"5d505646cf6d4fe581014ab2"} |
"arrayField": | ["hello",{"$numberInt":"10"}] | ["hello",10] |
"dateField": | {"$date":{"$numberLong":"1565546054692"}} | {"$date":"2019-08-11T17:54:14.692Z"} |
"dateBefore1970": | {"$date":{"$numberLong":"-1577923200000"}} | {"$date":{"$numberLong":"-1577923200000"}} |
"decimal128Field": | {"$numberDecimal":"10.99"} | {"$numberDecimal":"10.99"} |
"documentField": | {"a":"hello"} | {"a":"hello"} |
"doubleField": | {"$numberDouble":"10.5"} | 10.5 |
"infiniteNumber" | {"$numberDouble":"Infinity"} | {"$numberDouble":"Infinity"} |
"int32field": | {"$numberInt":"10"} | 10 |
"int64Field": | {"$numberLong":"50"} | 50 |
"minKeyField": | {"$minKey":1} | {"$minKey":1} |
"maxKeyField": | {"$maxKey":1} | {"$maxKey":1} |
"regexField": | {"$regularExpression":{"pattern":"^H","options":"i"}} | {"$regularExpression":{"pattern":"^H","options":"i"}} |
"timestampField": | {"$timestamp":{"t":1565545664,"i":1}} | {"$timestamp":{"t":1565545664,"i":1}} |
"uuid": | {"$uuid":"3b241101-e2bb-4255-8caf-4136c566a962"} | {"$uuid":"3b241101-e2bb-4255-8caf-4136c566a962"} |
Extended JSON Object Conversions
The following short examples create a document object and then convert the object to different forms using Extended JSON object conversion methods.
Setup
Create a document in the conversions
collection:
db.conversions.insertOne( { insertDate: new Date() } )
mongosh
returns a document object:
{ acknowledged: true, insertedId: ObjectId("61fbaf25671c45f3f5f4074a") }
EJSON.serialize
Serialize the data stored in a MongoDB document object:
serialized = EJSON.serialize( db.conversions.findOne() )
mongosh
parses a JavaScript object and returns values using
"$"
prefixed types:
{ _id: { '$oid': '61fbaf25671c45f3f5f4074a' }, insertDate: { '$date': '2022-02-03T10:32:05.230Z' } }
EJSON.deserialize
Deserialize a serialized object:
EJSON.deserialize( serialized )
mongosh
parses a JavaScript object and returns values using
the default mongosh
type form:
{ _id: new ObjectId( "61fbaf25671c45f3f5f4074a" ), insertDate: ISODate( "2022-02-03T10:32:05.230Z" ) }
EJSON.stringify
Convert an object to a string:
stringified = EJSON.stringify( db.conversions.findOne() )
mongosh
outputs the elements of the converted object as
strings:
{ "_id": {"$oid":"61fbaf25671c45f3f5f4074a"}, "insertDate":{"$date":"2022-02-03T10:32:05.230Z"} }
EJSON.parse
Parse a string to create an object:
EJSON.parse( stringified )
mongosh
returns the converted strings as documents:
{ _id: new ObjectId("61fbaf25671c45f3f5f4074a"), insertDate: ISODate("2022-02-03T10:32:05.230Z") }