Datalog Queries¶

Stratum includes a Datalog query engine that compiles Datalog patterns into SQL queries against the block database.

Opening the Query Panel¶

Click Query in the sidebar or navigate to /query.

The panel has two tabs:

Builder (default) — a visual filter builder: pick fields, operators and values; the generated Datalog is shown live and can be copied into the editor or run directly.
Datalog — the raw EDN editor for hand-written queries.

Both tabs share the same query state (Run, Save Query, Reset and the Saved Queries list work identically).

Visual Filter Builder¶

The Builder tab lets you compose a query without writing EDN:

Click Add condition to append a filter row.
Each row has a:
Combiner — how the row joins the previous one (AND / OR). The first row is always AND.
Field — the attribute to filter on (whitelisted, see table below).
Operator — the comparison for that field (options depend on the field).
Value — text/number/date input (hidden for "is set"/"is not set").
Rows can be reordered with the up/down arrows and removed with ×.
The Generated query preview shows the exact EDN that will be run. Copy it to the editor with the copy button, or press Run to execute it immediately.

Fields¶

Field	Attribute	Value type
Block text	`:block/content`	text
Marker	`:block/marker`	marker (TODO, DOING, DONE)
Priority	`:block/priority`	priority (A, B, C)
Page title	`:page/title`	text
Page path	`:page/path`	text
Block count	`:page/block_count`	number
Created	`:block/created`	date
Modified	`:block/modified`	date
Tags	`:block/tags`	tag
Has wiki-link	`:page/links`	page link

Operators¶

Operator	EDN generated	Meaning
equals	`[?b :block/marker "X"]`	equality
does not equal	`[(not= ?v "X")]`	inequality
contains	`[(clojure.string/includes? ?v "X")]`	substring
starts with	`[(clojure.string/starts-with? ?v "X")]`	prefix
`>` `<` `≥` `≤`	`[(> ?v "X")]` …	numeric/date comparison
is set	`[(present? ?v)]`	value exists
is not set	`[(absent? ?v)]`	value is NULL
has (tags / wiki-link)	`[?b :block/tags "x"]`	containment
does not have (tags / wiki-link)	`(not [?b :block/tags "x"])`	negation

Combiners and validity¶

Consecutive OR rows form a single (or ...) group; every OR group needs at least two rows. A lone OR row is reported as invalid and Run is disabled until fixed.
Every condition that requires a value must have one; otherwise the builder shows an inline error and disables Run.
"Does not have" (negation) cannot be nested inside an OR group — the builder emits it as a top-level (not ...) clause, so a group containing such a row is split.

Round-trip¶

When you switch from the Datalog tab back to the Builder, Stratum attempts to parse the editor content into builder rows. Queries the builder can understand (its own output or hand-written equivalents using whitelisted fields/operators) are converted; anything else — pull find specs, unknown attributes, JSON query syntax — shows a notice and keeps your current builder rows unchanged.

Query Syntax¶

Queries use Datalog syntax in EDN format:

{:query [:find ?variable1 ?variable2
         :where [?entity :attribute value]
                [?entity :attribute ?variable]]}

Components¶

Element	Description
`:find`	Variables to return (prefixed with `?`)
`:where`	Patterns that must match (entity-attribute-value triples)
`?entity`	A variable representing a block or page
`:attribute`	A block attribute (see table below)
`value`	A literal value or variable

Extended where-clause grammar¶

In addition to plain triples, :where accepts Logseq-compatible extended forms:

Predicate lists — [(<op> <arg>...)], e.g. [(not= ?m "DONE")], [(clojure.string/includes? ?c "foo")], [(> ?n "5")], [(present? ?m)], [(absent? ?m)]. Supported operators: = != not= > < >= <= contains? includes? clojure.string/includes? starts-with? clojure.string/starts-with? present? absent?. The variable must be bound to a plain column by an earlier triple.
Negation — (not <triple-or-predicate>), e.g. (not [?b :block/tags "x"]).
Or-groups — (or <clause> <clause> ...) with at least two clauses (triples or predicates), e.g. (or [?b :block/marker "TODO"] [?b :block/marker "DOING"]).
Ordering — :order-by [[?var :asc] ...] to order results by bound variables.

Block Attributes¶

The following attributes are available for querying:

Attribute	Type	Description
`:block/id`	UUID	Block unique identifier
`:block/content`	String	Block text content
`:block/marker`	String	Task marker (TODO, DOING, DONE)
`:block/priority`	String	Priority (A, B, C)
`:block/parent`	UUID	Parent block ID
`:block/page`	String	Containing page path
`:block/heading`	Number	Heading level (1-3)
`:block/collapsed`	Boolean	Is collapsed
`:block/properties`	Map	Key-value properties
`:block/tags`	Set	Block-level tags
`:page/title`	String	Page title from frontmatter
`:page/path`	String	Page file path
`:page/tags`	Set	Page frontmatter tags
`:page/block_count`	Number	Number of blocks
`:page/links`	Set	Wiki-link targets
`:page/backlinks`	Set	Incoming wiki-links

Examples¶

Find all TODO items¶

{:query [:find ?block ?content
         :where [?block :block/marker "TODO"]
                [?block :block/content ?content]]}

Find high-priority tasks¶

{:query [:find ?block ?content ?priority
         :where [?block :block/marker "TODO"]
                [?block :block/priority ?priority]
                [?block :block/content ?content]]}

Find blocks by tag¶

{:query [:find ?block ?content
         :where [?block :block/tags "project"]
                [?block :block/content ?content]]}

Find all pages with their block counts¶

{:query [:find ?page ?title ?count
         :where [?page :page/title ?title]
                [?page :page/block_count ?count]]}

Find recently modified pages¶

{:query [:find ?page ?title ?modified
         :where [?page :page/title ?title]
                [?page :page/modified ?modified]
         :order-by [[?modified :desc]]}

Find items with a marker other than DONE¶

{:query [:find ?block ?content
         :where [?block :block/marker ?marker]
                [(not= ?marker "DONE")]
                [?block :block/content ?content]]}

Or-groups and negation¶

{:query [:find ?block ?content
         :where (or [?block :block/marker "TODO"]
                    [?block :block/marker "DOING"])
                [?block :block/content ?content]]}

{:query [:find ?block ?content
         :where (not [?block :block/tags "project"])
                [?block :block/content ?content]]}

Query Results¶

Results are displayed in a table with:

Columns — labeled by your :find variables
Rows — each matching combination of values
Click a page path to navigate to that page

Saved Queries¶

You can save the current query under a name and reload it later. Saved queries are stored in .pkm/saved_queries.json inside your vault and sync with the vault, so they are available on every device where the vault is synced.

Saving the current query¶

With the query you want to keep in the editor:

Click Save Query (desktop) or Save (mobile) above the editor.
Enter a name in the dialog and click Save.

The name must not be empty. Leading and trailing whitespace is trimmed and names are limited to 256 characters.

Saving under a name that already exists overwrites the previous version of that saved query — it does not create a duplicate.

Viewing saved queries¶

The Saved Queries list below the results shows every saved query with its name and the last-updated date. Use the refresh button to reload the list.

Loading a saved query¶

Click a saved query in the list to load its query text into the editor. The query is not executed automatically — click Run Query (or Run) to run it.

Renaming a saved query¶

Use the rename (pencil) icon next to a saved query, enter the new name, and confirm. Renaming to a name that already exists fails and keeps the original name.

Deleting a saved query¶

Use the delete (trash) icon next to a saved query, then confirm in the dialog. Deletion cannot be undone.

Error handling and limitations¶

A missing or corrupt saved_queries.json is treated as an empty list; the next save rewrites a valid file.
Writes are atomic, so a crash or power loss cannot leave a half-written file behind.
Errors loading the list are shown in an error banner; errors during save, rename, or delete are shown in a warning banner.
Saving an empty query is allowed — the store does not validate the query syntax.

Tips¶

Start with the example queries by clicking Reset
Use ?block as your first variable to identify blocks
Combine markers and tags for powerful filtering: ?block :block/marker "TODO" + ?block :block/tags "project"
Results are live — run queries after editing to see changes
The visual builder only exposes whitelisted fields; for anything else (e.g. pull find specs) use the Datalog tab directly