CREATE TABLE student(rollno INT PRIMARY KEY, fname VARCHAR(15), lname VARCHAR(15), course_id VARCHAR(15),FOREIGN KEY (course_id) REFERENCES courses(course_id), major VARCHAR(23), age SMALLINT);
CREATE TABLE courses(course_id VARCHAR(15) PRIMARY KEY, course_name VARCHAR(15));

INSERT INTO student VALUES (405, 'Ramesh','Acharya', '89GW', 'BSCIT', 19 );
INSERT INTO student VALUES (306, 'Anil', 'Agarwal', '78NI', 'BCOM', 20);
INSERT INTO student VALUES (406, 'Sujita', 'Patel', '78NI', 'BCOM', 21);
INSERT INTO student VALUES (109, 'Harsh', 'Anand', 'ER9B', 'MATHEMATICS', 22);
INSERT INTO student VALUES (320, 'Ram', 'Reddy', '89GW', 'BSCIT', 23);

INSERT INTO courses VALUES('89GW', 'BSCIT');
INSERT INTO courses VALUES('78NI', 'BCOM');
INSERT INTO courses VALUES('ER9B', 'MATHEMATICS');
INSERT INTO courses VALUES('FE54', 'B.M.S');
INSERT INTO courses VALUES ('AE45', 'B.I.M');

SELECT course_name, fname, rollno
FROM student, courses
WHERE age > 25;

--Display the total number of student enrolled in each course except BSCIT
SELECT COUNT(*) as count, courses.course_name
FROM courses
JOIN student 
ON student.course_id = courses.course_id
WHERE course_name <> 'BSCIT'
GROUP BY courses.course_name;

--List the details of all the student whose course name begin with letter B
SELECT * 
FROM student
WHERE major LIKE 'B%';

SELECT *
FROM student
WHERE major = 'MATHEMATICS' OR major = 'BSCIT';

--List the name of the courses that do not have any students enrolled
SELECT course_name
FROM courses
WHERE course_id NOT IN ( SELECT course_id FROM student);

MySQL online editor

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About MySQL

MySQL is a open-source, free and very popular relational database management system which is developed, distributed and supported by Oracle corporation.

Key Features:

  • Open-source relational database management systems.
  • Reliable, very fast and easy to use database server.
  • Works on client-server model.
  • Highly Secure and Scalable
  • High Performance
  • High productivity as it uses stored procedures, triggers, views to write a highly productive code.
  • Supports large databases efficiently.
  • Supports many operating systems like Linux*,CentOS*, Solaris*,Ubuntu*,Windows*, MacOS*,FreeBSD* and others.

Syntax help

Commands

1. CREATE

CREATE TABLE table_name (
                column1 datatype,
                column2 datatype,
                ....);

Example

CREATE TABLE EMPLOYEE (
  empId INTEGER PRIMARY KEY,
  name TEXT NOT NULL,
  dept TEXT NOT NULL
);

2. ALTER

ALTER TABLE Table_name ADD column_name datatype;

Example

INSERT INTO EMPLOYEE VALUES (0001, 'Dave', 'Sales');

3. TRUNCATE

TRUNCATE table table_name;

4. DROP

DROP TABLE table_name;

5. RENAME

RENAME TABLE table_name1 to new_table_name1;

6. COMMENT

Single-Line Comments:

 --Line1;

Multi-Line comments:

   /* Line1,
   Line2 */

DML Commands

1. INSERT

INSERT INTO table_name (column1, column2, column3, ...) VALUES (value1, value2, value3, ...);

Note: Column names are optional.

Example

INSERT INTO EMPLOYEE VALUES (0001, 'Ava', 'Sales');

2. SELECT

SELECT column1, column2, ...
FROM table_name
[where condition];

Example

SELECT * FROM EMPLOYEE where dept ='sales';

3. UPDATE

UPDATE table_name
SET column1 = value1, column2 = value2, ...
WHERE condition;

Example

UPDATE EMPLOYEE SET dept = 'Sales' WHERE empId='0001';

4. DELETE

DELETE FROM table_name where condition;

Example

DELETE from EMPLOYEE where empId='0001';

Indexes

1. CREATE INDEX

  CREATE INDEX index_name on table_name(column_name);
  • To Create Unique index:
  CREATE UNIQUE INDEX index_name on table_name(column_name);

2. DROP INDEX

DROP INDEX index_name ON table_name;

Views

1. Create a View

Creating a View:
CREATE VIEW View_name AS 
Query;

2. How to call view

SELECT * FROM View_name;

3. Altering a View

ALTER View View_name AS 
Query;

4. Deleting a View

DROP VIEW View_name;

Triggers

1. Create a Trigger

CREATE TRIGGER trigger_name trigger_time trigger_event
    ON tbl_name FOR EACH ROW [trigger_order] trigger_body
/* where
trigger_time: { BEFORE | AFTER }
trigger_event: { INSERT | UPDATE | DELETE }
trigger_order: { FOLLOWS | PRECEDES } */

2. Drop a Trigger

DROP TRIGGER [IF EXISTS] trigger_name;

Stored Procedures

1. Create a Stored Procedure

CREATE PROCEDURE sp_name(p1 datatype)
BEGIN
/*Stored procedure code*/
END;

2. How to call Stored procedure

CALL sp_name;

3. How to delete stored procedure

DROP PROCEDURE sp_name;

Joins

1. INNER JOIN

SELECT * FROM TABLE1 INNER JOIN TABLE2 where condition;

2. LEFT JOIN

SELECT * FROM TABLE1 LEFT JOIN TABLE2 ON condition;

3. RIGHT JOIN

SELECT * FROM TABLE1 RIGHT JOIN TABLE2 ON condition;

4. CROSS JOIN

SELECT select_list from TABLE1 CROSS JOIN TABLE2;