Aug 5, 2024
SHOW DATABASES; कमांड द्वारा डेटाबेस दिखानाCREATE TABLE student (id INT NOT NULL PRIMARY KEY, name VARCHAR(30), address VARCHAR(30), marks INT);DESC student;INSERT INTO student (name, id, address, marks) VALUES ('Kamal', 12, 'Delhi', 79);INSERT INTO student VALUES ('Kamal', 12, 'Delhi', 79);INSERT INTO student (name, id, address, marks) VALUES ('Ram', 17, 'Delhi', 90), ('Shyam', 18, 'Mumbai', 88);SELECT * FROM student;SELECT name, id FROM student;SELECT * FROM student WHERE id = 12;UPDATE student SET address = 'Dehradun' WHERE id = 45;ALTER TABLE student ADD phone_number INT;ALTER TABLE student DROP COLUMN phone_number;DELETE FROM student WHERE name = 'Kamal';SELECT SUM(marks) FROM student;SELECT AVG(marks) FROM student;SELECT COUNT(name) FROM student;SELECT MAX(marks) FROM student;SELECT MIN(marks) FROM student;SELECT * FROM student ORDER BY marks ASC;SELECT * FROM student ORDER BY marks DESC;SELECT * FROM student INNER JOIN employee ON student.id = employee.id;SELECT * FROM student LEFT JOIN employee ON student.id = employee.id;SELECT * FROM student CROSS JOIN employee;इन नोट्स का उपयोग करते हुए आप SQL की प्रमुख अवधारणाओं को समझ सकते हैं और उन्हें आसानी से याद रख सकते हैं।