Improve Azure Functions example with new named results features. (#72)

Author: pinodeca

examples/azure-functions/sql/03_start_workflow.sql

@@ -5,61 +5,65 @@
 -- 4) Marks document processed/failed
 
 SELECT df.start(
-    $$SELECT COALESCE(
-          (
-            SELECT jsonb_build_object('id', id, 'content', content)::text
-            FROM demo.af_documents
-            WHERE status = 'pending'
-            ORDER BY id
-            LIMIT 1
-          ),
-          'null'
-      )$$ |=> 'doc'
-    ~> df.if(
-      $$SELECT (($doc)::jsonb) IS NOT NULL$$,
-      (
+    -- 1. Fetch one pending document
+    $$SELECT id, content FROM demo.af_documents
+        WHERE status = 'pending'
+        ORDER BY id
+        LIMIT 1
+    $$ |=> 'doc'
+
+    ~> df.if_rows('doc',
+
+        -- 2. Build & send HTTP request
         ($$SELECT jsonb_build_object(
-              'document_id', ((($doc)::jsonb->>'id')::bigint),
-              'text', (($doc)::jsonb->>'content'),
-            'max_tokens', 20,
-            'overlap_tokens', 5,
-              'language', 'en'
-          )::text$$ |=> 'requestbody')
-        ~> (df.http(
-            '{azure_function_base_url}/api/chunk_text',
-            'POST',
-            '$requestbody',
-            ('{"Content-Type":"application/json","x-functions-key":"{azure_function_key}"}')::jsonb,
-            60
-        ) |=> 'chunkresponse')
+                'document_id', $doc.id,
+                'text',        $doc.content,
+                'max_tokens',  20,
+                'overlap_tokens', 5,
+                'language',    'en'
+            )::text$$ |=> 'requestbody')
+
+        ~> (
+            df.http(
+                '{azure_function_base_url}/api/chunk_text',
+                'POST',
+                '$requestbody',
+                '{"Content-Type":"application/json","x-functions-key":"{azure_function_key}"}'::jsonb,
+                60
+            ) |=> 'resp')
+
+        -- 3. Parse response fields
+        ~> ($$SELECT ($resp::jsonb->>'ok')::boolean AS ok,
+                     $resp::jsonb->>'body' AS body$$ |=> 'r')
+
+        -- 4. Branch on success/failure
         ~> df.if(
-            $$SELECT ($chunkresponse::jsonb->>'ok')::boolean$$,
-            (
-                $$WITH payload AS (
-                      SELECT (($chunkresponse::jsonb->>'body')::jsonb) AS body_json
-                  )
-                  INSERT INTO demo.af_document_chunks (document_id, chunk_index, chunk_text, token_count)
-                  SELECT
-                      (payload.body_json->>'document_id')::bigint,
-                      (c->>'chunk_index')::int,
-                      c->>'text',
-                      (c->>'token_count')::int
-                  FROM payload, jsonb_array_elements(payload.body_json->'chunks') AS c$$
-                ~> $$UPDATE demo.af_documents
-                    SET status = 'processed',
-                        processed_at = now(),
-                        total_tokens = ((($chunkresponse::jsonb->>'body')::jsonb->>'total_tokens')::int),
-                        last_error = NULL
-                    WHERE id = ((($doc)::jsonb->>'id')::bigint)$$
-            ),
+            $$SELECT $r.ok$$,
+
+            -- Success: insert chunks, then mark processed
+            $$INSERT INTO demo.af_document_chunks (document_id, chunk_index, chunk_text, token_count)
+                SELECT $doc.id,
+                (c->>'chunk_index')::int,
+                c->>'text',
+                (c->>'token_count')::int
+            FROM jsonb_array_elements(($r.body)::jsonb->'chunks') AS c$$
+            ~> $$UPDATE demo.af_documents
+                SET status = 'processed',
+                processed_at = now(),
+                total_tokens = (($r.body)::jsonb->>'total_tokens')::int,
+                last_error = NULL
+                WHERE id = $doc.id$$,
+
+            -- Failure: mark failed
             $$UPDATE demo.af_documents
-              SET status = 'failed',
-                  processed_at = now(),
-                  last_error = 'HTTP ' || ($chunkresponse::jsonb->>'status') || ': ' || coalesce(($chunkresponse::jsonb->>'body'), '')
-              WHERE id = ((($doc)::jsonb->>'id')::bigint)$$
-        )
-      ),
-      $$SELECT 'no pending documents'$$
+                SET status = 'failed',
+                processed_at = now(),
+                last_error = 'HTTP ' || ($resp::jsonb->>'status') || ': ' || coalesce($r.body, '')
+                WHERE id = $doc.id$$
+        ),
+
+        -- No pending documents
+        $$SELECT 'no pending documents'$$
     ),
     'azure-functions-chunk-text'
 ) AS instance_id;