Add dbt semantic layer with time spine and sales metrics

README.md

@@ -34,6 +34,21 @@ performance improvements (idempotent indexes) on raw tables and select marts.
 
 ---
 
+## dbt Semantic Layer
+
+This project defines a dbt Semantic Layer on top of the Olist marts:
+
+- **Semantic model**: `olist_sales_daily` on top of `mart_olist__sales_daily`
+  - Time dimension: `order_date` (day granularity)
+  - Measures: `daily_revenue`, `daily_orders`, `daily_items`
+- **Metrics**:
+  - `total_revenue` (simple metric on `daily_revenue`)
+  - `total_orders` (simple metric on `daily_orders`)
+- **Time spine**:
+  - `time_spine_daily` – one row per `date_day` between 2016-01-01 and 2018-12-31, declared as the project time spine for MetricFlow.
+
+---
+
 ## Project Structure
 ```text
 dbt_project/

dbt_project/models/marts/olist/schema.yml

@@ -47,10 +47,12 @@ models:
               - order_id
               - order_item_id
 
-
   - name: mart_olist__sales_daily
+    time_spine:
+      standard_granularity_column: order_date
     columns:
       - name: order_date
+        granularity: day
         tests: [not_null, unique]
       - name: orders
         tests:

dbt_project/models/marts/olist/semantic_sales.yml

@@ -0,0 +1,50 @@
+semantic_models:
+  - name: olist_sales_daily
+    description: "Daily sales metrics for Olist; one row per day."
+    model: ref('mart_olist__sales_daily')
+
+    # Dimensión de tiempo principal
+    defaults:
+      agg_time_dimension: order_date
+
+    # Entidad lógica dueña de las dimensiones/medidas
+    entities:
+      - name: olist_day
+        type: primary
+
+    dimensions:
+      - name: order_date
+        type: time
+        type_params:
+          time_granularity: day
+
+    measures:
+      - name: daily_revenue
+        description: "Total revenue per day."
+        agg: sum
+        expr: revenue
+
+      - name: daily_orders
+        description: "Total number of orders per day."
+        agg: sum
+        expr: orders
+
+      - name: daily_items
+        description: "Total items sold per day."
+        agg: sum
+        expr: items
+
+metrics:
+  - name: total_revenue
+    description: "Total revenue across all days."
+    label: Total revenue
+    type: simple
+    type_params:
+      measure: daily_revenue
+
+  - name: total_orders
+    description: "Total number of orders."
+    label: Total orders
+    type: simple
+    type_params:
+      measure: daily_orders