feat: create dataset for tagging

models/courses/course_tags.sql

@@ -0,0 +1,39 @@
+with
+    most_recent_overviews as (
+        select org, course_key, max(modified) as last_modified
+        from {{ source("event_sink", "course_overviews") }}
+        group by org, course_key
+    ),
+    most_recent_course_tags as (
+        select
+            course_key,
+            display_name as course_name,
+            splitByString('+', course_key)[-1] as course_run,
+            org,
+            JSONExtract(course_data_json, 'tags', 'String') as tags_str
+        from {{ source("event_sink", "course_overviews") }} co
+        inner join
+            most_recent_overviews mro
+            on co.org = mro.org
+            and co.course_key = mro.course_key
+            and co.modified = mro.last_modified
+    ),
+    parsed_tags as (
+        select
+            course_key,
+            course_name,
+            JSONExtractKeys(tags_str) as taxonomy,
+            JSONExtractKeysAndValues(tags_str, 'String') as tags_keys,
+            arrayJoin(tags_keys) as taxonomy_tuple,
+            taxonomy_tuple .1 as taxonomy_name,
+            taxonomy_tuple .2 as tags_array_str,
+            JSONExtractArrayRaw(tags_array_str) as tags,
+            trim(BOTH '\"\"' from arrayJoin(tags)) as tag
+        from most_recent_course_tags
+    )
+select course_key, course_name, taxonomy_name, tag, lineage
+from parsed_tags
+inner join
+    {{ source("event_sink", "object_tag") }} as ot
+    on (course_key = object_id)
+    and (parsed_tags.tag = _value)

models/courses/sources.yml

@@ -32,3 +32,15 @@ sources:
           - name: modified
           - name: dump_id
           - name: time_last_dumped
+
+      - name: object_tag
+        columns:
+          - name: id
+          - name: object_id
+          - name: taxonomy
+          - name: tag
+          - name: _value
+          - name: _export_id
+          - name: lineage
+          - name: dump_id
+          - name: time_last_dumped