 -- 1. Create the table Employee with ecode as a primary key and insert the given rows in the table.
CREATE TABLE Employee (
    ecode INT PRIMARY KEY,
    ename VARCHAR(100),
    desig VARCHAR(100),
    dept VARCHAR(100),
    Salary INT,
    doj DATE
);

-- Inserting data into the Employee table
INSERT INTO Employee VALUES
(101, 'Rinkoo Sharma', 'MNGR', 'ACCTS', 80000, '2010-10-01'),
(102, 'Shiv Bansal', 'CLRK', 'ADMIN', 45000, '2012-01-04'),
(103, 'Raman Ahuja', 'EXEC', 'ADMIN', 95000, '2009-03-01'),
(104, 'Aman Sharma', 'SALESMAN', 'SALES', 55000, '2009-01-01'),
(105, 'Seema Singh', 'MNGR', 'SALES', 85000, '2008-02-01'),
(106, 'Aman Singh', 'SALESMAN', 'SALES', 45000, '2006-12-12'),
(107, 'Rajat Singh', 'CLRK', 'ACCTS', 35000, '2009-10-01');

-- 2. Display the details of all the employees in order of their department and name.
SELECT * FROM Employee ORDER BY dept, ename;

-- 3. Display the Employee code, Employee name, and salary of all Managers and Executives.
SELECT ecode, ename, Salary FROM Employee WHERE desig IN ('MNGR', 'EXEC');

-- 4. Increase the salary of all clerks by 10%.
UPDATE Employee SET Salary = Salary * 1.1 WHERE desig = 'CLRK';

-- 5. Display Department-wise maximum, minimum, and average salary paid.
SELECT dept, MAX(Salary) AS max_salary, MIN(Salary) AS min_salary, AVG(Salary) AS avg_salary
FROM Employee
GROUP BY dept;

-- 6. Display the Number of Employees in each designation.
SELECT desig, COUNT(*) AS num_employees FROM Employee GROUP BY desig;

-- 7. Display the difference between maximum salary and minimum salary for each category.
SELECT 
    desig,
    MAX(Salary) - MIN(Salary) AS salary_difference
FROM Employee
GROUP BY desig;

-- 8. Display average salary of each category.
SELECT 
    desig,
    AVG(Salary) AS avg_salary
FROM Employee
GROUP BY desig;

-- 9. Display employees with a salary less than 50000.
SELECT ename, dept FROM Employee WHERE Salary < 50000;

-- 10. Display salary in ascending order.
SELECT * FROM Employee ORDER BY Salary ASC;

-- 11. Display salary in descending order.
SELECT * FROM Employee ORDER BY Salary DESC;

-- 12. Display employees with Date of Joining after January 1, 2004.
SELECT * FROM Employee WHERE doj > '2008-02-01';

-- 13. Display the sum of all salaries.
SELECT SUM(Salary) AS total_salary FROM Employee;

-- 14. Display the length of each employee name.
SELECT ename, LENGTH(ename) AS name_length FROM Employee;

-- 15. Change a specific name.
UPDATE Employee SET ename = 'Aman Kapoor' WHERE ename = 'Aman Sharma';
-- 16 Add a new row
INSERT INTO Employee VALUES (108, 'New Employee', 'CLERK', 'ADMIN', 40000, '2022-01-22');

-- 17 Delete a specific row
DELETE FROM Employee WHERE ecode = 107;

-- 18 Add a new column
ALTER TABLE Employee ADD COLUMN bonus INT;

-- 19 Delete a specific column
ALTER TABLE Employee DROP COLUMN doj;

-- 20 Add data to the 'bonus' column.
UPDATE Employee SET bonus = 5000 WHERE ecode = 101;

-- 21 Display name and department of each employee.
SELECT ename, dept FROM Employee;
SELECT * FROM Employee

created 1 year ago

MySQL online editor

Write, Run & Share MySQL queries online using OneCompiler's MySQL online editor and compiler for free. It's one of the robust, feature-rich online editor and compiler for MySQL. Getting started with the OneCompiler's MySQL editor is really simple and pretty fast. The editor shows sample boilerplate code when you choose language as 'MySQL' and start writing queries to learn and test online without worrying about tedious process of installation.

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;