Query DWN Records
You can use the query
function to obtain records and protocols from a DWN. This guide shows how to do both, as well as how to sort the query results.
Querying a DWN is analogous to querying a database, and the flow of a query is similar to an SQL select statement.
A query can be read as select records with a filter of X from the DWN of this DID.
Querying Protocols​
The following snippet queries the local DWN for protocols that match a given schema:
Querying Records​
The following snippet queries a given DWN for records that match a given schema and are in a specific data format.
Note the
from
property used here. Much like SQL, where theFROM
command is used to specify which table to select data from, in Web5,from
specifies which DWN to query.
records.query()
does not guarantee that the data is returned unless it is under a specific threshold (50 kb).
To guarantee record data, call records.read().
Filterable Record Properties​
Here are the properties you can use to filter your record query, along with explanations and examples for each.
Property | Value | Example |
---|---|---|
recipient | Recipient DID of message | "did:example:alice" |
protocol | The URI of the protocol bucket in which to query | "example.com" |
protocolPath | Records under a protocol path across all context IDs | "example" |
contextId | recordId of a root record of a protocol | "bafyreianzpmhbgcgam5mys722vnsiuwn..." |
schema | The URI of the schema bucket in which to query | "https://schema.org/Message" |
recordId | Property contains the message recordId | "aa36ec55-c59b-4f20-8143-10f74aac696d" |
parentId | recordId of the parent record in a protocol | "iadsfdreianzpmasdffcgam5mys722vnd..." |
dataFormat | The IANA string for the data format to filter | "application/json" |
dateCreated | Date the record was created | "2023-04-30T22:49:37.713976Z" |
tags | User-defined key-value pairs for categorizing records | {"genre": "Action", "year": "2024"} |
Filter by parentId​
This snippet queries the DWN for records that have a parent record with a specific record ID:
Filter by protocol and protocolPath​
Given the following protocol definition is installed:
Playlist Protocol Definition
And assuming playlist
and video
records have been created using this protocol, the following snippet demonstrates how to query for video records that match the protocol:
Sorting Query Results​
Query results can be sorted via the dateSort
field. Valid values for dateSort
are:
Value | Sorts Results By | Order |
---|---|---|
createdAscending | dateCreated | ascending |
createdDescending | dateCreated | descending |
publishedAscending | datePublished | ascending |
publishedDescending | datePublished | descending |
Ascending Order​
This code snippet queries for records with a plain text data format, and returns them in ascending order by the date they were published:
Descending Order​
This code snippet queries for protocols with a certain URL, and returns them in descending order by the date they were created.
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