feat: add sql solution to lc problem: No.1972

No.1972.First and Last Call On the Same Day

Author: yanglbme

solution/1900-1999/1972.First and Last Call On the Same Day/README.md

@@ -67,7 +67,45 @@ Calls table:
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```sql
-
+# Write your MySQL query statement below
+with s as (
+    select
+        *
+    from
+        Calls
+    union
+    all
+    select
+        recipient_id,
+        caller_id,
+        call_time
+    from
+        Calls
+),
+t as (
+    select
+        caller_id user_id,
+        first_value(recipient_id) over(
+            partition by date_format(call_time, '%Y-%m-%d'),
+            caller_id
+            order by
+                call_time asc
+        ) first,
+        first_value(recipient_id) over(
+            partition by date_format(call_time, '%Y-%m-%d'),
+            caller_id
+            order by
+                call_time desc
+        ) last
+    from
+        s
+)
+select
+    distinct user_id
+from
+    t
+where
+    first = last
 ```
 
 <!-- tabs:end -->

solution/1900-1999/1972.First and Last Call On the Same Day/README_EN.md

@@ -64,7 +64,45 @@ On 2021-08-11, user 1 and 5 had a call. This call was the only call for both of
 ### **SQL**
 
 ```sql
-
+# Write your MySQL query statement below
+with s as (
+    select
+        *
+    from
+        Calls
+    union
+    all
+    select
+        recipient_id,
+        caller_id,
+        call_time
+    from
+        Calls
+),
+t as (
+    select
+        caller_id user_id,
+        first_value(recipient_id) over(
+            partition by date_format(call_time, '%Y-%m-%d'),
+            caller_id
+            order by
+                call_time asc
+        ) first,
+        first_value(recipient_id) over(
+            partition by date_format(call_time, '%Y-%m-%d'),
+            caller_id
+            order by
+                call_time desc
+        ) last
+    from
+        s
+)
+select
+    distinct user_id
+from
+    t
+where
+    first = last
 ```
 
 <!-- tabs:end -->

solution/1900-1999/1972.First and Last Call On the Same Day/Solution.sql

@@ -0,0 +1,39 @@
+# Write your MySQL query statement below
+with s as (
+    select
+        *
+    from
+        Calls
+    union
+    all
+    select
+        recipient_id,
+        caller_id,
+        call_time
+    from
+        Calls
+),
+t as (
+    select
+        caller_id user_id,
+        first_value(recipient_id) over(
+            partition by date_format(call_time, '%Y-%m-%d'),
+            caller_id
+            order by
+                call_time asc
+        ) first,
+        first_value(recipient_id) over(
+            partition by date_format(call_time, '%Y-%m-%d'),
+            caller_id
+            order by
+                call_time desc
+        ) last
+    from
+        s
+)
+select
+    distinct user_id
+from
+    t
+where
+    first = last