fix: ban JOIN to diamond/gold detail tables for cost queries to prevent row duplication

ai/signatures.py

@@ -57,25 +57,30 @@ class AnalyzeAndPlan(dspy.Signature):
       → Still filter by sales_order.status = 'closed'.
 
     COMPONENT COST BY PRODUCT (diamond cost, gold cost, making charges per product):
-      → The sales_table_v2_sales_order_line_pricing table has ALL component costs
-        and quantity in ONE place. Use it exclusively for cost analysis.
-      → Correct formula:  SUM(component_amount_per_unit * quantity)
-      → Columns available:
-          diamond_amount_per_unit  → total diamond cost = SUM(diamond_amount_per_unit * quantity)
-          gold_amount_per_unit     → total gold cost    = SUM(gold_amount_per_unit * quantity)
-          making_charges_per_unit  → total making cost  = SUM(making_charges_per_unit * quantity)
+      → sales_table_v2_sales_order_line_pricing has ALL cost columns AND quantity.
+        It is SELF-SUFFICIENT. NO JOIN to any other table is needed for cost queries.
+      → Correct formula:  SUM(column * quantity)  — multiply every time, never skip.
+      → Columns (all in sales_order_line_pricing):
+          diamond_amount_per_unit  → SUM(diamond_amount_per_unit * quantity)
+          gold_amount_per_unit     → SUM(gold_amount_per_unit * quantity)
+          making_charges_per_unit  → SUM(making_charges_per_unit * quantity)
       → GROUP BY product_id for "by product", GROUP BY variant_sku for "by variant/SKU".
-      → Example — top 10 products by diamond cost:
-            SELECT product_id, SUM(diamond_amount_per_unit * quantity) AS diamond_cost
-            FROM sales_table_v2_sales_order_line_pricing
-            GROUP BY product_id
+      → Always prefix the column with the table alias to avoid ambiguity.
+
+      EXACT TEMPLATE — top 10 products by diamond cost:
+            SELECT lp.product_id,
+                   SUM(lp.diamond_amount_per_unit * lp.quantity) AS diamond_cost
+            FROM sales_table_v2_sales_order_line_pricing lp
+            GROUP BY lp.product_id
             ORDER BY diamond_cost DESC
             LIMIT 10
-      → NEVER use sales_order_line_diamond or sales_order_line_gold tables for cost totals.
-        Those detail tables have diamond_amount_per_unit WITHOUT quantity — using SUM on them
-        directly gives WRONG results (undercounts because it ignores how many units were ordered).
-        Use them ONLY when the question asks about specific diamond/gold properties
-        (e.g. shape, quality, karat, size, carats) — NOT for cost or revenue calculations.
+
+      CRITICAL — DO NOT JOIN sales_order_line_diamond or sales_order_line_gold for costs:
+        • Those detail tables have MULTIPLE rows per sol_id (one per diamond type/shape/quality).
+        • Joining them multiplies every pricing row by the number of detail rows → WRONG totals.
+        • They have no quantity column → SUM(diamond_amount_per_unit) there is also WRONG.
+        • Only use those detail tables when the question explicitly asks about diamond/gold
+          PROPERTIES such as shape, quality, karat, carat weight, size — NOT for cost/revenue.
 
     PURCHASE ORDER TOTALS:
       → Use: purchase_orders_v6_purchase_order.total_amount
@@ -219,22 +224,24 @@ class SQLGeneration(dspy.Signature):
        - Highest/biggest/top "purchase order" → purchase_orders_v6_purchase_order ORDER BY total_amount DESC
        - Highest/biggest/top "order" or "sale" → sales_table_v2_sales_order ORDER BY total_amount DESC
 
-    3. COMPONENT COSTS (diamond/gold/making charges) — USE PRICING TABLE WITH QUANTITY:
-       - Correct table:  sales_table_v2_sales_order_line_pricing
-       - Correct formula: SUM(diamond_amount_per_unit * quantity)  for diamond cost
-                          SUM(gold_amount_per_unit * quantity)     for gold cost
-                          SUM(making_charges_per_unit * quantity)  for making charges
-       - NEVER use sales_order_line_diamond or sales_order_line_gold for cost aggregations.
-         Those tables lack quantity, so SUM(diamond_amount_per_unit) there is always WRONG.
-       - Examples:
+    3. COMPONENT COSTS (diamond/gold/making charges) — PRICING TABLE ONLY, NO JOINS:
+       - ONE table only: sales_table_v2_sales_order_line_pricing (alias: lp)
+       - Formula: SUM(lp.diamond_amount_per_unit * lp.quantity)   for diamond cost
+                  SUM(lp.gold_amount_per_unit * lp.quantity)      for gold cost
+                  SUM(lp.making_charges_per_unit * lp.quantity)   for making charges
+       - Always use table alias prefix (lp.product_id, lp.quantity, etc.) — never bare column names.
+       - ZERO joins needed. DO NOT join sales_order_line_diamond or sales_order_line_gold.
+         Joining those tables introduces duplicate rows (they have multiple rows per sol_id),
+         which inflates every SUM by 2x, 3x, or more — silently wrong results.
+       - Exact templates:
            Top products by diamond cost:
-             SELECT product_id, SUM(diamond_amount_per_unit * quantity) AS diamond_cost
-             FROM sales_table_v2_sales_order_line_pricing
-             GROUP BY product_id ORDER BY diamond_cost DESC LIMIT 10
+             SELECT lp.product_id, SUM(lp.diamond_amount_per_unit * lp.quantity) AS diamond_cost
+             FROM sales_table_v2_sales_order_line_pricing lp
+             GROUP BY lp.product_id ORDER BY diamond_cost DESC LIMIT 10
            Top SKUs by gold cost:
-             SELECT variant_sku, SUM(gold_amount_per_unit * quantity) AS gold_cost
-             FROM sales_table_v2_sales_order_line_pricing
-             GROUP BY variant_sku ORDER BY gold_cost DESC LIMIT 10
+             SELECT lp.variant_sku, SUM(lp.gold_amount_per_unit * lp.quantity) AS gold_cost
+             FROM sales_table_v2_sales_order_line_pricing lp
+             GROUP BY lp.variant_sku ORDER BY gold_cost DESC LIMIT 10
 
     5. USE PRE-COMPUTED TOTALS — NEVER RECONSTRUCT THEM:
        - For order-level metrics (revenue, AOV): use sales_table_v2_sales_order.total_amount