Add views of COSTS table, include effectivity details.

git-svn-id: http://locode01.ad.dom/svn/WEBMIP/trunk@3017 248e525c-4dfb-0310-94bc-949c084e9493

Schema/V_MECO.vw

@@ -0,0 +1,25 @@
+CREATE OR REPLACE VIEW V_MECO AS
+SELECT metr_code
+      ,description
+      ,selling_price
+      ,cost_price
+      ,delivery_cost
+      ,regi_code
+      ,valid_from AS effective_from
+      ,least(nvl(valid_to
+                ,to_date('2099'
+                        ,'yyyy'))
+            ,nvl(next_valid_from
+                ,to_date('2099'
+                        ,'yyyy'))) AS effective_to
+  FROM (SELECT metr_code
+              ,description
+              ,selling_price
+              ,cost_price
+              ,delivery_cost
+              ,regi_code
+              ,valid_from
+              ,valid_to
+              ,lead(valid_from) over(PARTITION BY cost.metr_code, regi_code ORDER BY valid_from) AS next_valid_from
+          FROM costs cost
+         WHERE cost_type = 'MECO');