should be it

external/duckdb/extension/tpcds/dsdgen/queries/87.sql

@@ -0,0 +1,30 @@
+SELECT count(*)
+FROM ((SELECT DISTINCT c_last_name,
+                         c_first_name,
+                         d_date
+         FROM store_sales,
+              date_dim,
+              customer
+         WHERE store_sales.ss_sold_date_sk = date_dim.d_date_sk
+           AND store_sales.ss_customer_sk = customer.c_customer_sk
+           AND d_month_seq BETWEEN 1200 AND 1200+11)
+      EXCEPT
+        (SELECT DISTINCT c_last_name,
+                         c_first_name,
+                         d_date
+         FROM catalog_sales,
+              date_dim,
+              customer
+         WHERE catalog_sales.cs_sold_date_sk = date_dim.d_date_sk
+           AND catalog_sales.cs_bill_customer_sk = customer.c_customer_sk
+           AND d_month_seq BETWEEN 1200 AND 1200+11)
+      EXCEPT
+        (SELECT DISTINCT c_last_name,
+                         c_first_name,
+                         d_date
+         FROM web_sales,
+              date_dim,
+              customer
+         WHERE web_sales.ws_sold_date_sk = date_dim.d_date_sk
+           AND web_sales.ws_bill_customer_sk = customer.c_customer_sk
+           AND d_month_seq BETWEEN 1200 AND 1200+11)) cool_cust ;