 -- CREATE TABLe Worker(
--   WORKER_ID INT NOT NULL PRIMARY KEY AUTO_INCREMENT,
--   FIRST_NAME CHAR(25),
--   LAST_NAME CHAR(25),
--   SALARY INT(15),
--   JOINING_DATE DATETIME,
--   DEPARTMENT CHAR(25)
  
-- );

-- INSERT INTO Worker 
--   (WORKER_ID, FIRST_NAME, LAST_NAME,
--   SALARY, JOINING_DATE, DEPARTMENT)VALUES
    
--     (001, 'Monika', 'Arora', 100000, '14-02-20 09.00.00', 'HR'),
--     (002, 'Niharika', 'Verma', 80000, '14-06-11 09.00.00', 'Admin'),
--     (003, 'Vishal', 'Singhal', 300000, '14-02-20 09.00.00', 'HR'),
--     (004, 'Amitabh', 'Singh', 500000, '14-02-20 09.00.00', 'Admin'),
--     (005, 'Vivek', 'Bhati', 500000, '14-06-11 09.00.00', 'Admin'),
--     (006, 'Vipul', 'Diwan', 200000, '14-01-20 09.00.00', 'Account'),
--     (007, 'Satish', 'Kumar', 75000, '14-06-20 09.00.00', 'Account'),
--     (008, 'Geetika', 'Chauhan', 90000, '14-04-11 09.00.00', 'Admin');
    
--     select * from Worker;
    
--     -- Write an SQL query to fetch "FIRST_NAME" from Worker table using the alias name as <WORKER_NAME
--     SELECT FIRST_NAME AS WORKER_NAME from Worker;
    
--     -- Write an SQL query to fetch "FIRST_NAME" from Worker table in upper case.
--     SELECT upper(FIRST_NAME) from Worker;
    
--     -- Write an SQL query to fetch unique values of DEPARTMENT from Worker table.
--     SELECT DISTINCT DEPARTMENT from Worker;
    
--     -- Write an SQL query to print the first three characters of FIRST_NAME from Worker table.
--     SELECT substring(FIRST_NAME,1,3) from Worker;
    
--     -- Write an SQL query to print all worker details from the worker tabel order by FIRST_NAME Ascending.
--     SELECT * from Worker order by FIRST_NAME asc;
    
--     -- Write an SQL query to print all Worker details from worker tabel order by FIRST_NAME Ascending and DEPARTMENT Descending.
--     SELECT * from Worker order by FIRST_NAME asc, DEPARTMENT desc;    
--     SELECT * from Worker order by LAST_NAME desc;
    
--     -- Write an SQL query to print details of Workers with DEPARTMENT name as "Admin".
--     SELECT * from Worker where DEPARTMENT like 'Admin%';
    
--     -- Write an SQL query to print the FIRST_NAME from Worker table after removing white spaces from the right side.
--     SELECT RTRIM(FIRST_NAME) from Worker;
    
--     -- Write an SQL query to print the DEPARTMENT from Worker table after removing white spaces from the left side.
--     SELECT LTRIM(DEPARTMENT) from Worker;
    
--     -- Write an SQL query to print the FIRST_NAME from Worker table after replacing 'a' with 'A'.
--     SELECT REPLACE(FIRST_NAME, 'a', 'A')from Worker;
    
--     -- Write an SQL query to print details for Workers with the  first name as "Vipul" and "Satish" from Worker table.
--     SELECT * from Worker where FIRST_NAME in ("Vipul", "Satish");
    
--     -- Write an SQL query to print details of Workers excluding first names, "Vipul" and "Satish" from Worker table.
--     SELECT * from Worker where FIRST_NAME not in ("Vipul", "Satish");
    
--     -- Write an SQL query to print details of Workers with DEPARTMENT names as "Admin".
--     SELECT * from Worker where DEPARTMENT like "Admin%";
    
--     -- Write an SQL query to print details of Workers whose FIRST_NAME contains 'a'.
--     SELECT * from Worker where FIRST_NAME like '%a%';
    
--     -- Write an SQL query to print details of Workers whose FIRST_NAME ends 'a'.
--     SELECT * from Worker where FIRST_NAME like '%a';
     
--       -- Write an SQL query to print details of Workers whose FIRST_NAME ends with 'h' and contains six alphabets.
--       SELECT * from Worker where FIRST_NAME like '_____h';
      
--       -- Write an SQL query to print details of Workers whose SALARY lies between 100000 and 500000.
--       SELECT * from Worker where SALARY between 100000 and 500000;
       
--       -- Write an SQL query to print the FIRST_NAME and LAST_NAME from Worker table into a single column COMPLITE_NAME. A space char should separate them.
--       SELECT CONCAT(FIRST_NAME, ' ', LAST_NAME) AS 'COMPLITE_NAME' from Worker;
       
--       -- Write an SQL query to print details of the Workers who have joined in Feb'2014.
--       SELECT * from Worker where year(JOINING_DATE) = 2014 and month(JOINING_DATE) = 2;
      
--       -- Write an SQL query to fetch the count of employees working in the DEPARTMENT 'Admin'.
--       SELECT count(*) from Worker where DEPARTMENT = 'Admin';
      
--       -- Write an SQL query to fetch worker names with salaries >= 50000 and <= 100000.
--       SELECT CONCAT (FIRST_NAME, ' ', LAST_NAME) As WORKER_NAME, SALARY from Worker;
--       -- WHERE WORKER_ID IN (SELECT WORKER_ID FROM Worker WHERE SALARY BETWEEN 50000 AND 100000);
      
--       -- Write an SQL query to fetch the no. of Workers for each DEPARTMENT in the Descending order.
--       SELECT DEPARTMENT, count(WORKER_ID) No_of_Workers FROM Worker 
--       GROUP BY DEPARTMENT 
--       ORDER BY No_of_Workers DESC;
      
--       -- Write an SQL query to show the current date and time.
--       SELECT CURDATE();
      
--       -- Following MySQL query returns the current date and time:
--       SELECT NOW();
      
--       -- Write an SQL query to show the top n (say 10) records of a table.
--       SELECT * FROM Worker ORDER BY SALARY DESC LIMIT 10;
      
--       -- Following SQL Server query to show the top n (say 10) records of table.
--       -- SELECT TOP 10 * FROM Worker ORDER BY SALARY DESC;
      
--       -- Write an SQL query to show the second highest salary from a table.
--       SELECT max(SALARY) from Worker where SALARY not in (SELECT max(SALARY) from Worker);
--       SELECT max(SALARY) from Worker;
--       SELECT min(SALARY) from Worker;
--       SELECT min(SALARY) from Worker where SALARY not in (SELECT min(SALARY) from Worker);
      
--       -- Write an SQL query to fetch DEPARTMENTs along with the total salaries paid for each of them.
--       SELECT DEPARTMENT, sum(SALARY) from Worker group by DEPARTMENT;
      
--       -- Write an SQL query to fetch the names of workers who earn the highest salary.
--       SELECT FIRST_NAME, SALARY from Worker WHERE SALARY = (SELECT max(SALARY) from Worker);
      
--       -- Write an SQL query to fetch DEPARTMENT along with the total salaries paid for each of them.
--       SELECT DEPARTMENT, sum(SALARY) from Worker group by DEPARTMENT;
      
--       -- Write an SQL query to fetch the first 50% records from a table.
--       SELECT * FROM Worker WHERE WORKER_ID <= (SELECT count(WORKER_ID)/2 from Worker);
--       SELECT * FROM Worker WHERE WORKER_ID >= (SELECT count(WORKER_ID)/2 from Worker);
      
      
      CREATE TABLE Employees(Employee_id int, Employee_name varchar(250), Employee_DOB date, Department_ID int);
      
      CREATE TABLE Departments(Department_id int, Department_name varchar(250));
      
      INSERT INTO Departments(Department_id, Department_Name)
      VALUES(1,'Human Resources'),(2,'Development'),(3,'Sales'),(4,'Technical Support');
      
      INSERT INTO Employees(Employee_id, Employee_name, Employee_DOB, Department_ID)
      VALUES(1,'Alan Smith','19890101',1),
            (2,'Sultan Nader','19920101',1),
            (3,'Mohd Rasheed','19990101',3),
            (5,'Peter Hilton','19860101',NULL);
            
            SELECT Employee_id,Employee_name,Employee_DOB,Department_Name from Departments INNER JOIN Employees
              ON Departments.Department_ID = Employees.Department_ID;

created 2 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;