feat: add sql solution to lc problem: No.1127 (doocs#1090)

No.1127.User Purchase Platform

Author: yanglbme

.prettierrc

@@ -20,6 +20,7 @@
                 "solution/1000-1099/1097.Game Play Analysis V/Solution.sql",
                 "solution/1000-1099/1098.Unpopular Books/Solution.sql",
                 "solution/1100-1199/1113.Reported Posts/Solution.sql",
+                "solution/1100-1199/1127.User Purchase Platform/Solution.sql",
                 "solution/1100-1199/1174.Immediate Food Delivery II/Solution.sql",
                 "solution/1100-1199/1193.Monthly Transactions I/Solution.sql",
                 "solution/1200-1299/1205.Monthly Transactions II/Solution.sql",

solution/1100-1199/1127.User Purchase Platform/README.md

@@ -63,7 +63,32 @@ Result table:
 ### **SQL**
 
 ```sql
-
+# Write your MySQL query statement below
+WITH
+    s AS (
+        SELECT DISTINCT spend_date, 'desktop' AS platform FROM Spending
+        UNION
+        SELECT DISTINCT spend_date, 'mobile' AS platform FROM Spending
+        UNION
+        SELECT DISTINCT spend_date, 'both' AS platform FROM Spending
+    ),
+    t AS (
+        SELECT
+            user_id,
+            spend_date,
+            if(count(platform) = 2, 'both', platform) AS platform,
+            sum(amount) AS amount
+        FROM Spending
+        GROUP BY 1, 2
+    )
+SELECT
+    t1.*,
+    ifnull(sum(amount), 0) AS total_amount,
+    count(t2.user_id) AS total_users
+FROM
+    s AS t1
+    LEFT JOIN t AS t2 USING (spend_date, platform)
+GROUP BY 1, 2;
 ```
 
 <!-- tabs:end -->

solution/1100-1199/1127.User Purchase Platform/README_EN.md

@@ -67,7 +67,32 @@ On 2019-07-02, user 2 purchased using mobile <strong>only</strong>, user 3 purch
 ### **SQL**
 
 ```sql
-
+# Write your MySQL query statement below
+WITH
+    s AS (
+        SELECT DISTINCT spend_date, 'desktop' AS platform FROM Spending
+        UNION
+        SELECT DISTINCT spend_date, 'mobile' AS platform FROM Spending
+        UNION
+        SELECT DISTINCT spend_date, 'both' AS platform FROM Spending
+    ),
+    t AS (
+        SELECT
+            user_id,
+            spend_date,
+            if(count(platform) = 2, 'both', platform) AS platform,
+            sum(amount) AS amount
+        FROM Spending
+        GROUP BY 1, 2
+    )
+SELECT
+    t1.*,
+    ifnull(sum(amount), 0) AS total_amount,
+    count(t2.user_id) AS total_users
+FROM
+    s AS t1
+    LEFT JOIN t AS t2 USING (spend_date, platform)
+GROUP BY 1, 2;
 ```
 
 <!-- tabs:end -->

solution/1100-1199/1127.User Purchase Platform/Solution.sql

@@ -0,0 +1,26 @@
+# Write your MySQL query statement below
+WITH
+    s AS (
+        SELECT DISTINCT spend_date, 'desktop' AS platform FROM Spending
+        UNION
+        SELECT DISTINCT spend_date, 'mobile' AS platform FROM Spending
+        UNION
+        SELECT DISTINCT spend_date, 'both' AS platform FROM Spending
+    ),
+    t AS (
+        SELECT
+            user_id,
+            spend_date,
+            if(count(platform) = 2, 'both', platform) AS platform,
+            sum(amount) AS amount
+        FROM Spending
+        GROUP BY 1, 2
+    )
+SELECT
+    t1.*,
+    ifnull(sum(amount), 0) AS total_amount,
+    count(t2.user_id) AS total_users
+FROM
+    s AS t1
+    LEFT JOIN t AS t2 USING (spend_date, platform)
+GROUP BY 1, 2;