add function to build a basic entry with an offset for each item of a header

header_item_template.pgsql

@@ -1,10 +1,20 @@
-\timing
+DO $f$
-with j as (
+
+DECLARE _j jsonb;
+DECLARE _m text;
+
+BEGIN
+
+_j := $${"header":{"vendor":"Target","date":"10/12/2017","instrument":"Discover Card","module":"hdrio","total":47.74,"location":"Stow, OH","transaction":"purchase","offset":"dcard"},"item":[{"vend item":"HERBAL","amt":7.99,"account":"home supplies","item":"shampoo","reason":"hygiene"},{"vend item":"HERBAL","amt":7.99,"account":"home supplies","item":"conditioner","reason":"hygiene"},{"vend item":"BUILDING SET","amt":28.74,"account":"recreation","item":"legos","reason":"toys","qty":6,"uom":"ea"},{"vend item":"OH TAX","amt":3.02,"account":"sales tax","item":"sales tax","reason":"sales tax","rate":"0.0675"}]}$$;
+
+WITH
+j AS (
     SELECT
-$$
+        _j  jb
-    {"header":{"vendor":"Target","date":"10/12/2017","instrument":"Discover Card","module":"hdrio","total":47.74,"location":"Stow, OH","transaction":"purchase","offset":"dcard"},"item":[{"vend item":"HERBAL","amt":7.99,"account":"home supplies","item":"shampoo","reason":"hygiene"},{"vend item":"HERBAL","amt":7.99,"account":"home supplies","item":"conditioner","reason":"hygiene"},{"vend item":"BUILDING SET","amt":28.74,"account":"recreation","item":"legos","reason":"toys","qty":6,"uom":"ea"},{"vend item":"OH TAX","amt":3.02,"account":"sales tax","item":"sales tax","reason":"sales tax","rate":"0.0675"}]}
-$$::jsonb jb
 )
+
+--------build a duplicating cross join table------------------
+
     ,os AS (
         SELECT
             flag, 
@@ -19,6 +29,10 @@ $$::jsonb jb
                 ('OFFSET',-1,j.jb->'header'->>'offset')
             ) x (flag, sign, offs) ON TRUE
     )
+
+
+------------do the cross join against all the item elements-------------------
+
 ,build AS (
 SELECT
     array['item',rn::text]::text jpath
@@ -32,15 +46,27 @@ ORDER BY
     ae.rn ASC,
     os.flag ASC
 )
+
+-------------re-aggregate the items into a single array point called 'gl'---------------
+
 ,agg AS (
 SELECT
     jsonb_build_object('gl',jsonb_agg(row_to_json(b))) gl
 FROM
     build b
 )
+
+------------take the new 'gl' with array key-value pair and combine it with the original---------------
+
 SELECT
     jsonb_pretty(agg.gl||j.jb)
+INTO
+    _m
 FROM
     agg
-    CROSS JOIN j
+    CROSS JOIN j;
 
+    RAISE NOTICE '%', _m;
+    
+END
+$f$

ubm_schema.sql

@@ -123,6 +123,86 @@ CREATE TYPE srce_defn_schema AS (
 );
 
 
+SET search_path = evt, pg_catalog;
+
+--
+-- Name: build_hdr_item_mje_gl(jsonb); Type: FUNCTION; Schema: evt; Owner: -
+--
+
+CREATE FUNCTION build_hdr_item_mje_gl(_j jsonb) RETURNS jsonb
+    LANGUAGE plpgsql
+    AS $_$
+DECLARE _m text;
+
+BEGIN
+
+--_j := $${"header":{"vendor":"Target","date":"10/12/2017","instrument":"Discover Card","module":"hdrio","total":47.74,"location":"Stow, OH","transaction":"purchase","offset":"dcard"},"item":[{"vend item":"HERBAL","amt":7.99,"account":"home supplies","item":"shampoo","reason":"hygiene"},{"vend item":"HERBAL","amt":7.99,"account":"home supplies","item":"conditioner","reason":"hygiene"},{"vend item":"BUILDING SET","amt":28.74,"account":"recreation","item":"legos","reason":"toys","qty":6,"uom":"ea"},{"vend item":"OH TAX","amt":3.02,"account":"sales tax","item":"sales tax","reason":"sales tax","rate":"0.0675"}]}$$;
+
+WITH
+j AS (
+    SELECT
+        _j  jb
+)
+
+--------build a duplicating cross join table------------------
+
+    ,os AS (
+        SELECT
+            flag, 
+            sign,
+            x.offs
+        FROM
+            j
+            JOIN LATERAL
+            (
+                VALUES
+                ('ITEM',1,null),
+                ('OFFSET',-1,j.jb->'header'->>'offset')
+            ) x (flag, sign, offs) ON TRUE
+    )
+
+
+------------do the cross join against all the item elements-------------------
+
+,build AS (
+SELECT
+    array['item',rn::text]::text jpath
+    ,COALESCE(os.offs,ae.e->>'account') acct
+    ,(ae.e->>'amt')::numeric * os.sign amount
+FROM
+    j
+    LEFT JOIN LATERAL JSONB_ARRAY_ELEMENTS(J.JB->'item') WITH ORDINALITY ae(e,rn) ON TRUE
+    CROSS JOIN os
+ORDER BY
+    ae.rn ASC,
+    os.flag ASC
+)
+
+-------------re-aggregate the items into a single array point called 'gl'---------------
+
+,agg AS (
+SELECT
+    jsonb_build_object('gl',jsonb_agg(row_to_json(b))) gl
+FROM
+    build b
+)
+
+------------take the new 'gl' with array key-value pair and combine it with the original---------------
+
+SELECT
+    jsonb_pretty(agg.gl||j.jb)
+INTO
+    _j
+FROM
+    agg
+    CROSS JOIN j;
+
+RETURN _j;
+    
+END
+$_$;
+
+
 SET search_path = public, pg_catalog;
 
 --