EntityStore
EntityStore["type"] represents an empty entity store for entities of type "type".
EntityStore["type"->data] represents an entity store for entities of type "type" with properties and values defined by data.
EntityStore[{tspec1,tspec2,…}] represents an entity store for entities of multiple types.
EntityStore[RelationalDatabase[…]] constructs an entity store from the schema of an external database.
EntityStore[{tspec1,tspec2,...},dbspec] constructs an entity store by mapping table names in the database specified by dbspec to types as specified by the tspeci.
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