Updated get_dependencies macro to only show paths from root nodes

macros/get_dependencies.sql

@@ -1,63 +1,90 @@
 {% macro get_dependencies() %}
 
     {%- set sql -%}
-    -- one record for each direct parent & child pair of models in DAG
-    with direct_parents as (
+    -- one record for each node in the DAG (models and sources) and its direct parent
+    with direct_relationships as (
 
-    {%- for model in graph.nodes.values() | selectattr("resource_type", "equalto", "model") -%} {# what about sources with no children?? #}
+    {%- for model in graph.nodes.values() | selectattr("resource_type", "equalto", "model") -%}
     {%- set outer_loop = loop -%}
 
-        {%- for model_parent in model.refs -%}
+        {%- if model.depends_on.nodes|length == 0 -%}
 
         select 
             '{{model.name}}' as model,
-            '{{model_parent.0}}' as parent,
-            'model' as parent_type
-        {% if not outer_loop.last %}union all{% endif %}
+            NULL as direct_parent,
+            NULL as direct_parent_type  {# if this field still useful? if not could simply by looping through depends_on.nodes instead of refs & sources seperately #}
 
-        {% endfor -%}
+        {%- else -%}       
 
-        {%- for source_parent in model.sources -%}
+            {%- for model_parent in model.refs -%}
+
+            select 
+                '{{model.name}}' as model,
+                '{{model_parent.0}}' as direct_parent,
+                'model' as direct_parent_type
+            {% if not loop.last %}union all{% endif %}
+
+            {% endfor -%}
+
+            {%- for source_parent in model.sources -%}
+
+            {% if loop.first and model.refs|length > 0 %}union all{% endif %}
+            select 
+                '{{model.name}}' as model,
+                '{{source_parent.0}}.{{source_parent.1}}' as direct_parent,
+                'source' as direct_parent_type
+            {% if not loop.last %}union all{% endif %}
+
+            {% endfor -%}
+
+        {%- endif -%}
 
-        select 
-            '{{model.name}}' as model,
-            '{{source_parent.0}}.{{source_parent.1}}' as parent,
-            'source' as parent_type
         {% if not outer_loop.last %}union all{% endif %}
 
-        {% endfor -%}
+    {% endfor -%}
+
+    {%- for source in graph.sources.values() -%}
 
-    {%- endfor -%}
+        {% if loop.first and graph.nodes|length > 0 %}union all{% endif %}
+        select 
+            '{{source.source_name}}.{{source.name}}' as model,
+            NULL as direct_parent,
+            NULL as direct_parent_type 
+        {% if not loop.last %}union all{% endif %}
+
+    {% endfor -%}
 
     ),
 
     -- recursive CTE
+    -- one record for every root node and each of its downstream children (including itself)
     all_relationships as (
 
         -- anchor 
         select 
-            parent as parent,
+            model as parent,
             model as child,
-            1 as distance,
-            array_construct(parent, child) as path -- snowflake-specific, but helpful for troubleshooting right now
-        from direct_parents
-        --where parent_type = 'source'
+            0 as distance,
+            array_construct(child) as path {# snowflake-specific, but helpful for troubleshooting right now #}
+        from direct_relationships
+        where direct_parent is null
 
         union all
 
         -- recursive clause
         select  
             all_relationships.parent as parent,
-            direct_parents.model as child, 
+            direct_relationships.model as child, 
             all_relationships.distance+1 as distance,
-            array_append(all_relationships.path, direct_parents.model) as path
-        from direct_parents
+            array_append(all_relationships.path, direct_relationships.model) as path
+        from direct_relationships
         inner join all_relationships
-            on all_relationships.child = direct_parents.parent
+            on all_relationships.child = direct_relationships.direct_parent
 
     )
 
     select * from all_relationships
+    order by parent, distance
 
     {%- endset -%}