# Document

Document is the basic unit of data in Nitrite database. It is a JSON like field-value pairs. The field is always a String and value can be anything including null. Document is schema-less, which means you can store any kind of data in a document.

Nitrite document supports nested document. That means, a value of a field can be another document. This allows you to create complex data structure.

More details on document can be found here.

Potassium Nitrite provides a set of extension functions to make document manipulation easier.

To create a document, you can use the documentOf function. It takes a vararg of Pair<String, Any?> and returns a Document.

val document = documentOf("firstName" to "John", "lastName" to "Doe")

To create a nested document, you can use the documentOf function recursively.

val document = documentOf(
    "firstName" to "John",
    "lastName" to "Doe",
    "address" to documentOf(
        "street" to "123 Main Street",
        "city" to "New York",
        "state" to "NY",
        "zip" to "10001"
    ),
    "phone" to listOf("212-555-1234", "646-555-4567")
)

To create an empty document, you can use the emptyDocument function.

val document = emptyDocument()

To get a field value from a document, you can use the index operator [] on the document. It takes a String as the field name and returns the value of the field.

val firstName = document["firstName"]

To check if a document is empty, you can use the isEmpty function. It takes no argument and returns a Boolean.

val isEmpty = document.isEmpty()

Conversely, to check if a document is not empty, you can use the isNotEmpty function. It takes no argument and returns a Boolean.

val isNotEmpty = document.isNotEmpty()