Added better solution and corrected the schema

Author: thecoddiwompler

Quiet Students in all the Exams/new_solution.sql

@@ -0,0 +1,42 @@
+WITH cte AS(
+    SELECT
+        b.student_id,
+        b.student_name,
+        a.score,
+        RANK() over(
+            PARTITION by exam_id
+            ORDER BY
+                score DESC
+        ) top_rank,
+        RANK() over(
+            PARTITION by exam_id
+            ORDER BY
+                score
+        ) bottom_rank
+    FROM
+        school.students b
+        LEFT OUTER JOIN school.exams a ON a.student_id = b.student_id
+),
+anti_sol AS(
+    SELECT
+        student_id,
+        student_name
+    FROM
+        cte
+    WHERE
+        top_rank = 1
+        OR bottom_rank = 1
+        OR score IS NULL
+)
+SELECT
+    student_id,
+    student_name
+FROM
+    school.students
+WHERE
+    student_id NOT IN (
+        SELECT
+            student_id
+        FROM
+            anti_sol
+    );

Restaurant Growth/schema.sql

@@ -1,13 +1,65 @@
-Create table If Not Exists Customer (customer_id int, name varchar(20), visited_on date, amount int)
-Truncate table Customer
-insert into Customer (customer_id, name, visited_on, amount) values ('1', 'Jhon', '2019-01-01', '100')
-insert into Customer (customer_id, name, visited_on, amount) values ('2', 'Daniel', '2019-01-02', '110')
-insert into Customer (customer_id, name, visited_on, amount) values ('3', 'Jade', '2019-01-03', '120')
-insert into Customer (customer_id, name, visited_on, amount) values ('4', 'Khaled', '2019-01-04', '130')
-insert into Customer (customer_id, name, visited_on, amount) values ('5', 'Winston', '2019-01-05', '110')
-insert into Customer (customer_id, name, visited_on, amount) values ('6', 'Elvis', '2019-01-06', '140')
-insert into Customer (customer_id, name, visited_on, amount) values ('7', 'Anna', '2019-01-07', '150')
-insert into Customer (customer_id, name, visited_on, amount) values ('8', 'Maria', '2019-01-08', '80')
-insert into Customer (customer_id, name, visited_on, amount) values ('9', 'Jaze', '2019-01-09', '110')
-insert into Customer (customer_id, name, visited_on, amount) values ('1', 'Jhon', '2019-01-10', '130')
-insert into Customer (customer_id, name, visited_on, amount) values ('3', 'Jade', '2019-01-10', '150')
+CREATE TABLE IF NOT EXISTS Customer (
+    customer_id int,
+    name varchar(20),
+    visited_on date,
+    amount int
+);
+
+TRUNCATE TABLE Customer;
+
+INSERT INTO
+    Customer (customer_id, name, visited_on, amount)
+VALUES
+    ('1', 'Jhon', '2019-01-01', '100');
+
+INSERT INTO
+    Customer (customer_id, name, visited_on, amount)
+VALUES
+    ('2', 'Daniel', '2019-01-02', '110');
+
+INSERT INTO
+    Customer (customer_id, name, visited_on, amount)
+VALUES
+    ('3', 'Jade', '2019-01-03', '120');
+
+INSERT INTO
+    Customer (customer_id, name, visited_on, amount)
+VALUES
+    ('4', 'Khaled', '2019-01-04', '130');
+
+INSERT INTO
+    Customer (customer_id, name, visited_on, amount)
+VALUES
+    ('5', 'Winston', '2019-01-05', '110');
+
+INSERT INTO
+    Customer (customer_id, name, visited_on, amount)
+VALUES
+    ('6', 'Elvis', '2019-01-06', '140');
+
+INSERT INTO
+    Customer (customer_id, name, visited_on, amount)
+VALUES
+    ('7', 'Anna', '2019-01-07', '150');
+
+INSERT INTO
+    Customer (customer_id, name, visited_on, amount)
+VALUES
+    ('8', 'Maria', '2019-01-08', '80');
+
+INSERT INTO
+    Customer (customer_id, name, visited_on, amount)
+VALUES
+    ('9', 'Jaze', '2019-01-09', '110');
+
+INSERT INTO
+    Customer (customer_id, name, visited_on, amount)
+VALUES
+    ('1', 'Jhon', '2019-01-10', '130');
+
+INSERT INTO
+    Customer (customer_id, name, visited_on, amount)
+VALUES
+    ('3', 'Jade', '2019-01-10', '150');
+
+COMMIT;