Roam EDN Structure

Written 2021-01-25

The structure is a datascript database in Clojure's native EDN format.
The initial object in the database defines the schema, and this is not particular interesting for most uses.
After that comes the :datoms, which contain all the graph data.
- Each datom is an entry in entity-attribute-value (EAV) format.
- That is, each is a list of the format: [entity-id "attribute-name" value tx-id], where tx-id is the ID of the database transaction in which the item was most recently modified.

Attributes

Each page and block is a single entity, and each has multiple attributes. An entity can also have multiple values for a particular attribute. Generally simply mean that the attribute appears multiple times on the entity, with a different value each time.
Attributes on Pages and Blocks
- :block/uid - A unique ID for the block, different from the datascript entity id. This is the same id that you see in block references.
- :block/children - The IDs of the direct children of this block or page.
- :block/refs - A list of UIDs referenced by a block, by links, hashtags, attributes, etc. Here we see the block reference in string format, as well as a "refs" value that indicates the actual block id.
  - ```
   [82509 :block/children 82528 536905570]
   [82509 :block/open true 536905536]
   [82509 :block/order 0 536905536]
   [82509 :block/page 82508 536905537]
   [82509 :block/parents 82508 536905537]
   [82509 :block/refs 80137 536905571] ;; The page with UID mniPrpzKa
   [82509 :block/string "((91b26967-bd3c-4ce7-abf7-100ba848c90a))" 536905570]
   [82509 :block/uid "u_EGyfOOI" 536905536]
   [82509 :create/email "daniel@danielmfeld.com" 536905536]
   [82509 :create/time 1610571818743 536905536]
   [82509 :edit/email "daniel@danielmfeld.com" 536905536]
   [82509 :edit/time 1610571818743 536905536]
```
- :create/email - The email of the user that created this block
- :create/time - A timestamp of when this block was created. Sometimes this is absent.
- :edit/email - The email of the last user to edit this block
- :edit/time - A timestamp of when this block was last edited
Block-only Attributes
- :block/heading - The heading level of the block.
- :block/parents - All the ancestor blocks of this one, up to the page it's in.
- :block/page - The entity ID of the page that this block is in.
- :block/open - If this block is expanded or collapsed
- :block/order - The order that this block appears relative to its sibling blocks.

Page-only Attributes

:node/title - The title of the page

:log/id - This appears on daily notes, and you can use the timestamp to determine which day the note is for.

[82511 :block/uid "01-14-2021" 536905548]
[82511 :create/email "daniel@danielmfeld.com" 536905548]
[82511 :create/time 1610620052622 536905548]
[82511 :edit/email "daniel@danielmfeld.com" 536905548]
[82511 :edit/time 1610620066797 536905565]
[82511 :log/id 1610620052621 536905548] ;; The timestamp
[82511 :node/title "January 14th, 2021" 536905548]

:entity/attrs - A set of all attributes and values referenced in a page.

Each item in the set is a list of three maps.
The :value of the second item is the attribute's UID.
The :value of the third is the attribute's value, either a string or a UID. The rest all seem to be the page's UID.
If an attribute has multiple values (i.e. multiple hashtags) there will be one entry for each value of the attribute.

[6367 :entity/attrs
 #{
  ;; The current page
 [{:source [:block/uid "BwqNL2PQq"], :value [:block/uid "BwqNL2PQq"]}
  ;; The UID of the attribute
 {:source [:block/uid "4NH7hu_Ow"], :value [:block/uid "hcB3qiqqa"]}
  ;; The UID of the attribute's value (when it's a link/hashtag)
 {:source [:block/uid "4NH7hu_Ow"], :value [:block/uid "x_lDM2Klh"]}]
 
 ;; The current page
[{:source [:block/uid "BwqNL2PQq"], :value [:block/uid "BwqNL2PQq"]}
 ;; The UID of the attribute
 {:source [:block/uid "Hg3Z0L4ap"], :value [:block/uid "gNlp2UsOV"]}
 ;; The string value of the attribute
 {:source [:block/uid "Hg3Z0L4ap"], :value " The Problems With Deliberate Practice"]}}

:attrs/lookup - I haven't looked into this much yet, but it appears to link to blocks in the page that reference attributes, and also to the attributes themselves.

;; The current page
[8718 :attrs/lookup 8718 536880551]
;; A block in this page that references an attribute
[8718 :attrs/lookup 8766 536880551]
;; The id of an attribute referenced inside this page
[8718 :attrs/lookup 8946 536880551]
[8718 :entity/attrs 
 #{
 [{:source [:block/uid "wWln_ysjZ"], :value [:block/uid "wWln_ysjZ"]}
  {:source [:block/uid "RBlQZRu5V"], :value [:block/uid "uZNZalyHW"]}
  {:source [:block/uid "RBlQZRu5V"], :value " https://scch.io/tutorials/deep-dive-into-css-grid-2"}]
} 536880551]