-- Creating the student table 
CREATE TABLE students(
  StudentID INT,
  FirstName VARCHAR(10),
  LastName VARCHAR(10),
  Major VARCHAR(25),
  gpa DECIMAL(2,1)
);

-- inserting the rows in the database
INSERT INTO students VALUE(1,"VASEEM","DURRANI","AI",7.8);
INSERT INTO students VALUE(2,"KULBIR","SINGH","AI",8.2);
INSERT INTO students VALUE(3,"KULBIR","SINGH","DS",8.3);
INSERT INTO students VALUE(4,"MITHUN","MISTRY","DS",9.1);
INSERT INTO students VALUE(5,"ANJALY","SOMAN","DS",8.9);
INSERT INTO students VALUE(6,"MONA","IBRAHIM","DA",9.2);
INSERT INTO students VALUE(7,"MUSTAFA","MUSTAFA","DA",9.0);

-- fetch the complete information of the table
-- SELECT* FROM students;
-- select Firstname,gpa from students;
-- fetching the data in the ordered from i.e ascending order w.r.t gpa
-- SELECT* from students ORDER BY gpa;

-- fetching the data in the ordered form ie. descending order w.r.t gpa
-- SELECT * FROM students ORDER BY gpa DESC;

-- top 3 students of the insitution
-- SELECT * FROM students ORDER BY gpa DESC limit 3;

-- fetching the database information of DS students
-- select* from students where major="DS";

-- fetching the database information of AI students
-- select* from students where major="AI";

-- fetching the database information of DA students
-- select* from students where major="DA";
-- Topper of DS
-- SELECT * FROM students WHERE Major ="DS" order by gpa DESC LIMIT 1;

-- SELECT * FROM students WHERE Major ="DA" order by gpa DESC LIMIT 1;
-- SELECT * FROM students WHERE Major ="AI" order by gpa DESC LIMIT 1;

Topper of DS  SELECT FirstName,gpa FROM students WHERE Major ="DS" order by gpa DESC LIMIT 1;
Topper of DA   SELECT FirstName,gpa FROM students WHERE Major ="DA" order by gpa DESC LIMIT 1;
Topper of AI SELECT FirstName,gpa FROM students WHERE Major ="AI" order by gpa DESC LIMIT 1;

-- updating the name of the Major
--update students
set major= "Data Sceince"
where major= "DS";
select* from students;

update students
set major= "Data Analytics"
where major= "DA";
select* from students;

update students
set major= "Artifical Intelligence"
where major= "AI";
select* from students;

-- select count(studentid) as total_number_of_student from students;

-- select avg(gpa) as averege_gpa from students;

-- select min(gpa) as min_gpa from students;

-- select max(gpa) as max_gpa from students;

-- average gpa for DS students
-- SELECT AVG(gpa) AS average_GPA_of_DS FROM students where Major = "DS";

-- average gpa for AI students
-- SELECT AVG(gpa) AS average_GPA_of_DS FROM students where Major = "AI";
-- average gpa for DA students
-- SELECT AVG(gpa) AS average_GPA_of_DS FROM students where Major = "DA";

-- AVG GPA for DS students
-- SELECT AVG(gpa) AS average_GPA_of_DS,MIN(gpa) AS min_gpa_DS, MAX(gpa) AS max_gpa_DS FROM students where Major = "Data Science";


-- AVG GPA for AI sutdents
SELECT AVG(gpa) AS average_GPA_of_AI,MIN(gpa) AS min_gpa_AI, MAX(gpa) AS max_gpa_Ai FROM students where Major = "Artificial Intelligence";

-- AVG GPA for DA students
SELECT AVG(gpa) AS average_GPA_of_DA,MIN(gpa) AS min_gpa_DA, MAX(gpa) AS max_gpa_DA FROM students where Major = "Data Analytics";

-- group by 
SELECT major, COUNT(StudentID) AS number_of_students, 
AVG(gpa) AS avg_gpa,MIN(gpa) AS min_gpa, MAX(gpa) AS max_gpa 
FROM students GROUP BY major;

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;