 -- CREATE TABLE employee (
--   Id INT PRIMARY KEY,
--   Name VARCHAR(45) NOT NULL,
--   Department VARCHAR(45) NOT NULL,
--   Salary FLOAT NOT NULL,
--   Gender VARCHAR(45) NOT NULL,
--   Age INT NOT NULL,
--   City VARCHAR(45) NOT NULL
-- );
-- INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1001, 'John Doe', 'IT', 35000, 'Male', 25, 'London');
-- INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1002, 'Mary Smith', 'HR', 45000, 'Female', 27, 'Mumbai');
-- INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1003, 'James Brown', 'Finance', 50000, 'Male', 28, 'Delhi');
-- INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1004, 'Mike Walker', 'Finance', 50000, 'Male', 28, 'London');
-- INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1005, 'Linda Jones', 'HR', 75000, 'Female', 26, 'Mumbai');
-- INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1006, 'Anurag Mohanty', 'IT', 35000, 'Male', 25, 'London');
-- INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1007, 'Priyanla Dewan', 'HR', 45000, 'Female', 27, 'Mumbai');
-- INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1008, 'Sambit Mohanty', 'IT', 50000, 'Male', 28, 'London');
-- INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1009, 'Pranaya Kumar', 'IT', 50000, 'Male', 28, 'London');
-- INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1010, 'Hina Sharma', 'HR', 75000, 'Female', 26, 'Mumbai');

-- SQL CLAUSES

-- 1. SELECT
-- SELECT Id, Name, Salary FROM employee;

-- 2. WHERE
-- SELECT Id, Name, Salary 
-- FROM employee
-- WHERE Department="HR";

-- 3. GROUP BY
-- SELECT 
--   Department AS "Dept", 
--   COUNT(Id) AS "#Emp"
-- FROM employee
-- GROUP BY Department;

-- 4. HAVING
-- SELECT 
--   Department AS "Dept", 
--   COUNT(Id) AS "#Emp"
-- FROM employee
-- GROUP BY Department
-- HAVING COUNT(Id) > 3;

-- 5. ORDER BY
-- SELECT Id, Name, Salary 
-- FROM employee
-- ORDER BY Id DESC, Name ASC;

-- 6. LIMIT
-- SELECT Id, Name, Salary
-- FROM employee
-- ORDER BY Salary DESC
-- LIMIT 5;

-- 7. AS
-- SELECT 
--   Id as EmpID,
--   Name as EmployeeName,
--   Department as Dept
-- FROM employee;


-- CONDITIONS & OPERATORS

CREATE TABLE employee (
  Id INT PRIMARY KEY,
  Name VARCHAR(45) NOT NULL,
  Department VARCHAR(45) NOT NULL,
  Salary FLOAT NOT NULL,
  Gender VARCHAR(45) NOT NULL,
  Age INT NOT NULL,
  City VARCHAR(45) NOT NULL
);
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1001, 'John Doe', 'IT', 35000, 'Male', 25, 'London');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1002, 'Mary Smith', 'HR', 45000, 'Female', 27, 'London');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1003, 'James Brown', 'Finance', 50000, 'Male', 28, 'London');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1004, 'Mike Walker', 'Finance', 50000, 'Male', 28, 'London');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1005, 'Linda Jones', 'HR', 75000, 'Female', 26, 'London');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1006, 'Anurag Mohanty', 'IT', 35000, 'Male', 25, 'Mumbai');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1007, 'Priyanla Dewan', 'HR', 45000, 'Female', 27, 'Mumbai');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1008, 'Sambit Mohanty', 'IT', 50000, 'Male', 28, 'Mumbai');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1009, 'Pranaya Kumar', 'IT', 50000, 'Male', 28, 'Mumbai');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1010, 'Hina Sharma', 'HR', 75000, 'Female', 26, 'Mumbai');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1011, 'Pramod Panda', 'IT', 45000, 'Male', 27, 'Mumbai');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1012, 'Preety Tiwary', 'HR', 55000, 'Female', 28, 'Mumbai');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1013, 'Santosh Dube', 'IT', 52000, 'Male', 28, 'Mumbai');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1014, 'Sara Talour', 'HR', 85000, 'Female', 26, 'London');
INSERT INTO employee (Id, `Name`, Department, Salary, Gender, Age, City) VALUES (1015, 'Pamela Kar', 'Finance', 70000, 'Female', 26, 'London');

-- True | False conditions
-- SELECT * 
-- FROM employee
-- WHERE NOT Department="HR";

-- Comparison > | < | >= | <= | = | <> | !=
-- SELECT * 
-- FROM employee
-- WHERE Salary <= 50000;

-- Logical Operators AND | OR | NOT
-- SELECT * FROM employee
-- WHERE Department="IT" AND Gender="Male" AND Salary > 40000;
-- SELECT * FROM employee
-- WHERE NOT (Department="HR" OR Department="IT");

-- LIKE Operator
-- % -> anything(varying length) | _ absolute limit(fixed length)
-- SELECT * FROM employee
-- WHERE Name LIKE "_a%";
-- SELECT * FROM employee
-- WHERE Department LIKE "__";

-- IN Operator
-- SELECT * FROM employee
-- WHERE Department IN ("HR", "IT");

-- BETWEEN Operator
-- SELECT * FROM employee
-- WHERE (Salary BETWEEN 45000 AND 50000);

-- Arithmatic Operators  + - / * % 
-- SELECT 200 + 100;
-- SELECT 200 - 100;
-- SELECT 200 / 100;
-- SELECT 200 * 100;
-- SELECT 200 % 199;
-- BODMAS Brackets Order Division Multiplication Addition Subtraction

-- Concatenation
-- SELECT CONCAT("Board", " ", "Infinity");
-- SELECT CONCAT(Id, "#", Name)
-- FROM employee;

-- Temporal Operators
SELECT (CURRENT_DATE - INTERVAL 7 DAY) as Date;

created 3 years 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;