SQL Challenges-1: Find Student Supporter
SQL Challenges-1: Exercise-15 with Solution
From the following table, write a SQL query to find those students who have referred by the teacher whose id not equal to 602. Return the student names.
Input:
Table: students
Structure:
Field | Type | Null | Key | Default | Extra |
---|---|---|---|---|---|
student_id | int(11) | YES | |||
student_name | varchar(25) | YES | |||
teacher_id | int(11) | YES |
Data:
student_id | student_name | teacher_id |
---|---|---|
1001 | Alex | 601 |
1002 | Jhon | |
1003 | Peter | |
1004 | Minto | 604 |
1005 | Crage | |
1006 | Chang | 601 |
1007 | Philip | 602 |
Sample Solution:
SQL Code(MySQL):
CREATE TABLE IF NOT EXISTS students (student_id INT,student_name VARCHAR(25),teacher_id INT);
TRUNCATE TABLE students;
CREATE TABLE IF NOT EXISTS students (student_id INT,student_name VARCHAR(25),teacher_id INT);
INSERT INTO students (student_id, student_name, teacher_id) values ('1001', 'Alex', '601');
INSERT INTO students (student_id, student_name, teacher_id) values ('1002', 'Jhon', NULL);
INSERT INTO students (student_id, student_name, teacher_id) values ('1003', 'Peter', NULL);
INSERT INTO students (student_id, student_name, teacher_id) values ('1004', 'Minto', '604');
INSERT INTO students (student_id, student_name, teacher_id) values ('1005', 'Crage', NULL);
INSERT INTO students (student_id, student_name, teacher_id) values ('1006', 'Chang', '601');
INSERT INTO students (student_id, student_name, teacher_id) values ('1007', 'Philip', '602');
SELECT student_name
FROM students WHERE teacher_id <> 602
OR teacher_id IS NULL;
Sample Output:
student_name| ------------| Alex | Jhon | Peter | Minto | Crage | Chang |
SQL Code Editor:
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