Finished Question 1 of 3-4

Kota Uchino · Kota Uchino · commit 675097e6aedd · 2018-01-10T23:16:34.000+09:00
diff --git a/3/3-4/1.sql b/3/3-4/1.sql
@@ -0,0 +1,16 @@
+SELECT
+  c.CustomerName
+, SUM(
+      CASE
+        WHEN s.Quantity IS NULL THEN 0
+        ELSE s.Quantity
+      END
+      ) AS 販売数量合計
+FROM
+  Customers AS c
+    LEFT OUTER JOIN
+  Sales AS s
+    ON  c.CustomerID = s.CustomerID
+GROUP BY
+  c.CustomerID
+;
