JSON types

JavaScript Object Notation (JSON) is a simple format for representing data. It requires very little markup and is flexible enough to represent the majority of data structures. It is self-describing, which makes it ideal for schemaless applications and searches. It can optionally be paired with a schema to define an expected structure.

Each JSON document contains one JSON value. A value can be one of a variety of JSON types. Some JSON types, such as JSON object and JSON array, allow JSON values to be nested to create complex structures.

{
  "stringProperty": "value1",
  "numberProperty": -123.456,
  "booleanProperty": false,
  "nullProperty": null,
  "objectProperty": 
  { 
    "childProperty": true 
  },
  "arrayProperty": 
  [ 
    "1", 
    2, 
    3.4, 
    true, 
    null, 
    { "child":"object" }, 
    [ "child", "array" ] 
  ]
}

The JSON data type is a field type in the FairCom server. Its length can be up to 2 billion bytes or be limited to a length between 1 and 65,500 bytes. The JSON data type is flexible because it may contain any number and a variety of properties and values, including objects, arrays, strings, numbers, true, false, and null. See Data types.

A table may contain a mix of JSON fields for flexibility and strongly typed fields for predictability. For maximum flexibility, a table may have as few as two fields; an "id" field to uniquely identify each record and a JSON field to store any possible value in each record.

A JSON value is the building block of JSON . A JSON value can stand alone or can be nested inside another JSON value.

A JSON value is strongly typed as one of the JSON types: JSON object, JSON array, JSON string, JSON number, JSON Boolean, or JSON null.

A JSON array contains one or more JSON values. Each JSON value may be any JSON type. An array starts with the left square bracket ([) character, contains zero or more values separated by the comma (, ) character, and ends with the right square bracket (]) character — for example, [ 1, 2, 3] or [ "a", "b", "c"].

Each value in a JSON array can be any type, but it is best practice for each value in a JSON array to have the same type, such as an array of strings, numbers, or objects where each object has the same structure.

[
 {
 "name": "mike",
 "eats": "pizza"
 },
 {
 "name": "teresa",
 "eats": "chocolate"
 }
]

A JSON object is a set of JSON properties. Each JSON property in an object must have a unique name. An object starts with the left curly bracket ({) character, contains zero or more properties separated by the comma (, ) character, and ends with the right curly bracket (}) character.

{
 "property1": "value1",
 "property2": false
} 

A JSON property has a name and a value where the name may be any string value and the value may be set to any JSON type.

The name part of a property begins with the quotation marks (") followed by one or more UTF-8 characters and ends with the quotation marks (").

The name is followed by the colon (:) character to separate it from the value.

The value may be any JSON type. Each type has its own formatting rules: JSON object, JSON array, JSON string, JSON number, JSON Boolean, or JSON null.

White space can be inserted between the parts of a JSON property and between the property and the JSON object that contains it.

"myProperty":"myValue" 

A JSON number value is a signed, decimal floating point number. It is represented as a sequence of ASCII numeric digits with an optional plus (+) or minus (-) character at the beginning and an optional decimal point in the middle — for example, -91.2247.

A JSON number is not a binary floating point number and does not have problems with rounding and precision, but some JSON parsers incorrectly convert it into a binary floating point number and create these problems. Thus, it is safest to represent numbers in JSON within a JSON string.

A JSON string value is a sequence of UTF-8 characters enclosed by a set of quotation marks ("").

Example string:

"my string"

There is no official limit to the number of characters in a string, but the practical limit is typically around 1 megabyte. The FairCom server supports JSON strings up to 2 GB in length.

JSON requires the characters in the following table to be escaped

A JSON Boolean value is true or false.

"childProperty": true 

A JSON null value is null. The convention in JSON is that omitting a property and setting it to null are the same thing. In contrast, setting a property to an empty value ("", {}, [], or [{}] ) are not the same thing as null. An application using JSON must determine the meaning of these empty values.