datomic

Interface Entity

public interface Entity

Implements the Entity API for associative navigation by attribute keys. An Entity is lazy - the values of its attributes are not obtained from the db until get or touch are called, after which they are cached in the entity. Note that entities have reference-like equality semantics - Two entities are equal if they have the same id and their databases have the same id

Method Summary

Modifier and Type	Method and Description
Database	db()
java.lang.Object	get(java.lang.Object key) Gets the value of the attribute named by key, and is polymorphic on key type cardinality :many attributes will always return a collection, even when only one value
java.util.Set<java.lang.String>	keySet()
Entity	touch() Touches all of the attributes of the entity, including any component entities recursively.

Method Detail

get

java.lang.Object get(java.lang.Object key)

Gets the value of the attribute named by key, and is polymorphic on key type cardinality :many attributes will always return a collection, even when only one value

Parameters:

key - A colon-prefixed string, e.g. ":user/firstName"

Returns:

the value(s) of that attribute, or null if none

touch

Entity touch()

Touches all of the attributes of the entity, including any component entities recursively.

Returns:

this Entity

keySet

java.util.Set<java.lang.String> keySet()

Returns:

the key names of the attributes

db

Database db()

Returns:

the database value that is the basis for this entity