feat: add solutions to lc problems: No.0262,0569,0618

* No.0262.Trips and Users
* No.0569.Median Employee Salary
* No.0618.Students Report By Geography

Author: yanglbme

solution/0200-0299/0262.Trips and Users/README.md

@@ -128,8 +128,26 @@ Users 表：
 
 ### **SQL**
 
-```
-
+```sql
+# Write your MySQL query statement below
+select
+    request_at Day,
+    round(avg(status != 'completed'), 2) 'Cancellation Rate'
+from
+    Trips t
+    join Users u1 on (
+        t.client_id = u1.users_id
+        and u1.banned = 'No'
+    )
+    join Users u2 on (
+        t.driver_id = u2.users_id
+        and u2.banned = 'No'
+    )
+where
+    request_at between '2013-10-01'
+    and '2013-10-03'
+group by
+    request_at
 ```
 
 <!-- tabs:end -->

solution/0200-0299/0262.Trips and Users/README_EN.md

@@ -114,8 +114,26 @@ On 2013-10-03:
 
 ### **SQL**
 
-```
-
+```sql
+# Write your MySQL query statement below
+select
+    request_at Day,
+    round(avg(status != 'completed'), 2) 'Cancellation Rate'
+from
+    Trips t
+    join Users u1 on (
+        t.client_id = u1.users_id
+        and u1.banned = 'No'
+    )
+    join Users u2 on (
+        t.driver_id = u2.users_id
+        and u2.banned = 'No'
+    )
+where
+    request_at between '2013-10-01'
+    and '2013-10-03'
+group by
+    request_at
 ```
 
 <!-- tabs:end -->

solution/0200-0299/0262.Trips and Users/Solution.sql

@@ -0,0 +1,19 @@
+# Write your MySQL query statement below
+select
+    request_at Day,
+    round(avg(status != 'completed'), 2) 'Cancellation Rate'
+from
+    Trips t
+    join Users u1 on (
+        t.client_id = u1.users_id
+        and u1.banned = 'No'
+    )
+    join Users u2 on (
+        t.driver_id = u2.users_id
+        and u2.banned = 'No'
+    )
+where
+    request_at between '2013-10-01'
+    and '2013-10-03'
+group by
+    request_at

solution/0500-0599/0569.Median Employee Salary/README.md

@@ -81,7 +81,28 @@ Employee 表:
 ### **SQL**
 
 ```sql
-
+# Write your MySQL query statement below
+with t as (
+    select
+        *,
+        row_number() over(
+            partition by company
+            order by
+                salary asc
+        ) rk,
+        count(id) over(partition by company) n
+    from
+        Employee
+)
+select
+    id,
+    company,
+    salary
+from
+    t
+where
+    rk >= n / 2
+    and rk <= n / 2 + 1;
 ```
 
 <!-- tabs:end -->

solution/0500-0599/0569.Median Employee Salary/README_EN.md

@@ -108,7 +108,28 @@ For company C, the rows sorted are as follows:
 ### **SQL**
 
 ```sql
-
+# Write your MySQL query statement below
+with t as (
+    select
+        *,
+        row_number() over(
+            partition by company
+            order by
+                salary asc
+        ) rk,
+        count(id) over(partition by company) n
+    from
+        Employee
+)
+select
+    id,
+    company,
+    salary
+from
+    t
+where
+    rk >= n / 2
+    and rk <= n / 2 + 1;
 ```
 
 <!-- tabs:end -->

solution/0500-0599/0569.Median Employee Salary/Solution.sql

@@ -0,0 +1,22 @@
+# Write your MySQL query statement below
+with t as (
+    select
+        *,
+        row_number() over(
+            partition by company
+            order by
+                salary asc
+        ) rk,
+        count(id) over(partition by company) n
+    from
+        Employee
+)
+select
+    id,
+    company,
+    salary
+from
+    t
+where
+    rk >= n / 2
+    and rk <= n / 2 + 1;

solution/0600-0699/0618.Students Report By Geography/README.md

@@ -65,7 +65,26 @@ Student table:
 ### **SQL**
 
 ```sql
-
+# Write your MySQL query statement below
+with t as (
+    select
+        *,
+        row_number() over(
+            partition by continent
+            order by
+                name
+        ) rn
+    from
+        Student
+)
+select
+    max(if(continent = 'America', name, null)) America,
+    max(if(continent = 'Asia', name, null)) Asia,
+    max(if(continent = 'Europe', name, null)) Europe
+from
+    t
+group by
+    rn
 ```
 
 <!-- tabs:end -->

solution/0600-0699/0618.Students Report By Geography/README_EN.md

@@ -60,7 +60,26 @@ Student table:
 ### **SQL**
 
 ```sql
-
+# Write your MySQL query statement below
+with t as (
+    select
+        *,
+        row_number() over(
+            partition by continent
+            order by
+                name
+        ) rn
+    from
+        Student
+)
+select
+    max(if(continent = 'America', name, null)) America,
+    max(if(continent = 'Asia', name, null)) Asia,
+    max(if(continent = 'Europe', name, null)) Europe
+from
+    t
+group by
+    rn
 ```
 
 <!-- tabs:end -->

solution/0600-0699/0618.Students Report By Geography/Solution.sql

@@ -0,0 +1,20 @@
+# Write your MySQL query statement below
+with t as (
+    select
+        *,
+        row_number() over(
+            partition by continent
+            order by
+                name
+        ) rn
+    from
+        Student
+)
+select
+    max(if(continent = 'America', name, null)) America,
+    max(if(continent = 'Asia', name, null)) Asia,
+    max(if(continent = 'Europe', name, null)) Europe
+from
+    t
+group by
+    rn