MongoDB Extended JSON (v2)

MongoDB Extended JSON v2 Usage

EJSON.serialize( db.<collection>.findOne() )

EJSON.deserialize( <serialized object> )

EJSON.stringify( <deserialized object> )

EJSON.parse( <string> )

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.

Array

[ <elements> ]

<Same as Canonical>

Where the array elements are as follows:

• <elements>

  • Array elements use Extended JSON.

  • To specify an empty array, omit the content [ ].

Binary

{ "$binary":
   {
      "base64": "<payload>",
      "subType": "<t>"
   }
}

<Same as Canonical>

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.

Date

For dates between years 1970 and 9999, inclusive:

{"$date": {"$numberLong": "<millis>"}}

{"$date": "<ISO-8601 Date/Time Format>"}

For dates before year 1970 or after year 9999:

{"$date": {"$numberLong": "<millis>"}}

<Same as Canonical>

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.

Decimal128

{ "$numberDecimal": "<number>" }

<Same as Canonical>

Where the values are as follows:

• "<number>"

  • A high-precision decimal as a string.

Document

{ <content> }

<Same as Canonical>

Where the document contents are as follows:

• <content>

  • Name:value pairs that use Extended JSON.

  • To specify an empty document, omit the content { }.

Double

For finite numbers:

{"$numberDouble": "<decimal string>" }

<non-integer number>

For infinite numbers or NAN:

{"$numberDouble": <"Infinity"|"-Infinity"|"NaN"> }

<Same as Canonical>

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.

Int64

{ "$numberLong": "<number>" }

<integer>

Where the values are as follows:

• "<number>"

  • A 64-bit signed integer as string.

• <integer>

  • A 64-bit signed integer.

Int32

{ "$numberInt": "<number>" }

<integer>

Where the values are as follows:

• "<number>"

  • A 32-bit signed integer as a string.

• <integer>

  • A 32-bit signed integer.

MaxKey

{ "$maxKey": 1 }

<Same as Canonical>

The MaxKey BSON data type compares higher than all other types. See Comparison/Sort Order for more information on comparison order for BSON types.

MinKey

{ "$minKey": 1 }

<Same as Canonical>

The MinKey BSON data type compares lower than all other types. See Comparison/Sort Order for more information on comparison order for BSON types.

ObjectId

{ "$oid": "<ObjectId bytes>" }

<Same as Canonical>

Where the values are as follows:

• "<ObjectId bytes>"

  • A 24-character, big-endian hexadecimal string that represents the ObjectId bytes.

Regular Expression

{ "$regularExpression":
   {
      "pattern": "<regexPattern>",
      "options": "<options>"
  }
}

<Same as Canonical>

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 ('g', 'i', 'm' and 's') or an empty string "".

  • Options other than ('g', 'i', 'm' and 's') will be dropped when converting to this representation.

  Important

  The options MUST be in alphabetical order.

Timestamp

{"$timestamp": {"t": <t>, "i": <i>}}

<Same as Canonical>

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.

db.conversions.insertOne( { insertDate: new Date() } )

{
  acknowledged: true,
  insertedId: ObjectId("61fbaf25671c45f3f5f4074a")
}

serialized = EJSON.serialize( db.conversions.findOne() )

{
  _id: { '$oid': '61fbaf25671c45f3f5f4074a' },
  insertDate: { '$date': '2022-02-03T10:32:05.230Z' }
}

EJSON.deserialize( serialized )

{
  _id: new ObjectId( "61fbaf25671c45f3f5f4074a" ),
  insertDate: ISODate( "2022-02-03T10:32:05.230Z" )
}

stringified = EJSON.stringify( db.conversions.findOne() )

{
   "_id": {"$oid":"61fbaf25671c45f3f5f4074a"},
   "insertDate":{"$date":"2022-02-03T10:32:05.230Z"}
}

EJSON.parse( stringified )

{
  _id: new ObjectId("61fbaf25671c45f3f5f4074a"),
  insertDate: ISODate("2022-02-03T10:32:05.230Z")
}