feat: add sql solution to lc problem: No.2494 (doocs#1144)

No.2494.Merge Overlapping Events in the Same Hall

Author: yanglbme

.prettierrc

@@ -37,6 +37,7 @@
                 "solution/2000-2099/2066.Account Balance/Solution.sql",
                 "solution/2200-2299/2230.The Users That Are Eligible for Discount/Solution.sql",
                 "solution/2600-2699/2686.Immediate Food Delivery III/Solution.sql",
+                "solution/2400-2499/2494.Merge Overlapping Events in the Same Hall/Solution.sql",
                 "solution/2700-2799/2752.Customers with Maximum Number of Transactions on Consecutive Days/Solution.sql"
             ],
             "options": {

solution/2400-2499/2494.Merge Overlapping Events in the Same Hall/README.md

@@ -73,7 +73,44 @@ HallEvents 表:
 <!-- 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
+            hall_id,
+            start_day,
+            end_day,
+            max(end_day) OVER (
+                PARTITION BY hall_id
+                ORDER BY start_day
+            ) AS cur_max_end_day
+        FROM HallEvents
+    ),
+    T AS (
+        SELECT
+            *,
+            if(
+                start_day <= lag(cur_max_end_day) OVER (
+                    PARTITION BY hall_id
+                    ORDER BY start_day
+                ),
+                0,
+                1
+            ) AS start
+        FROM S
+    ),
+    P AS (
+        SELECT
+            *,
+            sum(start) OVER (
+                PARTITION BY hall_id
+                ORDER BY start_day
+            ) AS gid
+        FROM T
+    )
+SELECT hall_id, min(start_day) AS start_day, max(end_day) AS end_day
+FROM P
+GROUP BY hall_id, gid;
 ```
 
 <!-- tabs:end -->

solution/2400-2499/2494.Merge Overlapping Events in the Same Hall/README_EN.md

@@ -68,7 +68,44 @@ Hall 3:
 ### **SQL**
 
 ```sql
-
+# Write your MySQL query statement below
+WITH
+    S AS (
+        SELECT
+            hall_id,
+            start_day,
+            end_day,
+            max(end_day) OVER (
+                PARTITION BY hall_id
+                ORDER BY start_day
+            ) AS cur_max_end_day
+        FROM HallEvents
+    ),
+    T AS (
+        SELECT
+            *,
+            if(
+                start_day <= lag(cur_max_end_day) OVER (
+                    PARTITION BY hall_id
+                    ORDER BY start_day
+                ),
+                0,
+                1
+            ) AS start
+        FROM S
+    ),
+    P AS (
+        SELECT
+            *,
+            sum(start) OVER (
+                PARTITION BY hall_id
+                ORDER BY start_day
+            ) AS gid
+        FROM T
+    )
+SELECT hall_id, min(start_day) AS start_day, max(end_day) AS end_day
+FROM P
+GROUP BY hall_id, gid;
 ```
 
 <!-- tabs:end -->

solution/2400-2499/2494.Merge Overlapping Events in the Same Hall/Solution.sql

@@ -0,0 +1,38 @@
+# Write your MySQL query statement below
+WITH
+    S AS (
+        SELECT
+            hall_id,
+            start_day,
+            end_day,
+            max(end_day) OVER (
+                PARTITION BY hall_id
+                ORDER BY start_day
+            ) AS cur_max_end_day
+        FROM HallEvents
+    ),
+    T AS (
+        SELECT
+            *,
+            if(
+                start_day <= lag(cur_max_end_day) OVER (
+                    PARTITION BY hall_id
+                    ORDER BY start_day
+                ),
+                0,
+                1
+            ) AS start
+        FROM S
+    ),
+    P AS (
+        SELECT
+            *,
+            sum(start) OVER (
+                PARTITION BY hall_id
+                ORDER BY start_day
+            ) AS gid
+        FROM T
+    )
+SELECT hall_id, min(start_day) AS start_day, max(end_day) AS end_day
+FROM P
+GROUP BY hall_id, gid;