 
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,'NIHRIKA','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,'14-06-20 09.00.00','ADMIN  '),
    (006,'VIPUL  ','DIWAN  ',200000,'14-06-11 09.00.00','ACCOUNT'),
    (007,'SATISH ','KUMAR  ',75000 ,'14-01-20 09.00.00','ACCOUNT'),
    (008,'GEETKA ','CHWHAN ',900000,'14-04-11 09.00.00','ADMIN  ');
    
    
    
    CREATE TABLE BONUS (
    WORKER_REF_ID INT,
    BONUS_AMOUNT INT(10),
    BONUS_DATE DATETIME,
    FOREIGN KEY (WORKER_REF_ID) REFERENCES WORKER(WORKER_ID) ON DELETE CASCADE 
    );
    
    
    INSERT INTO BONUS 
    (WORKER_REF_ID,BONUS_AMOUNT,BONUS_DATE) VALUES
    (001,5000,'16-02-20'),
    (002,3000,'16-06-11'),
    (003,4000,'16-02-20'),
    (001,4500,'16-02-20'),
    (002,3500,'16-06-11');
    
    
    
    CREATE TABLE TITLE(
    WORKER_REF_ID INT ,
    WORKER_TITLE CHAR(25),
    AFFECTED_FROM DATETIME,
    FOREIGN KEY (WORKER_REF_ID) REFERENCES WORKER(WORKER_ID) ON DELETE CASCADE
    );
    
    INSERT INTO TITLE 
    (WORKER_REF_ID,WORKER_TITLE,AFFECTED_FROM) VALUES
    (001,'MANAGER','2016-02-20'),
    (002,'EXECUTIVE','2016-06-11'),
    (008,'EXECUTIVE','2016-06-11'),
    (005,'MANAGER','2016-06-11'),
    (004,'ASST. MANAGER','2016-06-11'),
    (007,'EXECUTIVE','2016-06-11'),
    (006,'LEAD','2016-06-11'),
    (003,'LEAD','2016-06-11');
    
    -- SELECT * FROM WORKER;
    
  -- Q1-> FETCH FIRST NAME FROM WORKER TABLE
  -- SELECT FIRST_NAME FROM WORKER;
          -- SELECT FIRST_NAME FROM WORKER AS WORKER_NAME;
    
  -- Q2-> FETCH FIRST NAME FROM WORKER IN UPPERASE
  -- SELECT ucase(FIRST_NAME) AS WOKERS FROM WORKER;
          -- SELECT UPPER(FIRST_NAME) FROM WORKER AS WORKERS ;
    
  -- Q3-> FETCH UNIQUE VALUE OF DEPARTMENT
        -- SELECT DEPARTMENT FROM WORKER GROUP BY DEPARTMENT;
  
         -- SELECT DISTINCT DEPARTMENT FROM WORKER;
               -- OR ---USEING GROUP BY WITHOUT USING ANY AGGREGATION----
         -- SELECT DEPARTMENT FROM WORKER GROUP BY DEPARTMENT;  
      
  -- Q4-> FETCH FIRST 3 CHARACTER OF FIRST NAME FROM WORKER TABLE
    -- SELECT  SUBSTRING(FIRST_NAME,1,3) AS NAMESCD
    -- FROM WORKER ;
  
         -- SELECT SUBSTRING(FIRST_NAME,1,3) FROM WORKER;
    
  -- Q5-> FETCH POSITION OF THE ALPHABET 'b' IN THE FIRST NAME COLUMN 'AMITABH' FROM WORKER TABLE
          -- SELECT POSITION('B' IN FIRST_NAME) AS PO FROM WORKER WHERE FIRST_NAME IN ('AMITABH');
  
       -- SELECT POSITION('B' IN FIRST_NAME) FROM WORKER WHERE FIRST_NAME='AMITABH';
       --     -- OR WE CAN USE INSTR(STRINJG,CHARACTER)
       -- SELECT INSTR(FIRST_NAME,'B' ) FROM WORKER WHERE FIRST_NAME='AMITABH';
        
  -- Q6->find name of worker after trimming spaces from right
      -- SELECT RTRIM(FIRST_NAME) FROM WORKER;
      
  -- Q7-USE LTRIM TO REMOVE WHITE SPACES FROM left
      
  -- Q8-WRITE QUERY TO FETCH THE UNIQUE VALUE OF DEPARTMENT FROM WORKER TABLE AND PRINT ITS LENGTH
      SELECT DISTINCT DEPARTMENT, LENGTH(DEPARTMENT) FROM WORKER; 
      
  -- Q9-WRITE QUERY TO FETCH FIRST_NAME FROM WORKER AFTER REPLACING 'A' TO 'a';
      -- SELECT REPLACE(FIRST_NAME,'A','a') FROM WORKER ;
      
  -- Q10-WRITE COMPLETE NAME IN SINGLE COLUMN 'COMPLETE NAME' FROM WORKER
    -- SELECT CONCAT(FIRST_NAME," ",LAST_NAME) AS FULLNAME FROM WORKER;
  
  -- Q11-SQL QUERY TO PRINT ALL WORKER AND DEPT DESENDING DETAIL FROM WORKER ORDER BY FIRST_NAME ASCENDING
    -- SELECT * FROM WORKER ORDER BY FIRST_NAME;
      
  -- Q12-SQL QUERY TO PRINT ALL WORKER AND DEPT DESENDING DETAIL FROM WORKER ORDER BY FIRST_NAME ASCENDING AND DEPT DESENDING
    -- SELECT * FROM WORKER ORDER BY FIRST_NAME ASC,DEPARTMENT DESC ;
    
  -- Q13-FIND DETAILS OF VIPUL AND SATISH AS FIRST_NAME  
    -- SELECT * FROM WORKER WHERE FIRST_NAME IN ('SATISH','VIPUL');
                  -- OR
    -- SELECT * FROM WORKER WHERE FIRST_NAME ='SATISH' OR FIRST_NAME ='VIPUL';              
      
  -- Q14-NOW EXCLUDE SATISH AND VIPUL
    -- SELECT * FROM WORKER WHERE FIRST_NAME NOT IN ('SATISH','VIPUL');
      
  -- Q15-FIND DETAILS OF WORKER FROM ADMIN DEPARTMENT
    -- SELECT * FROM WORKER WHERE DEPARTMENT='ADMIN';
      
  -- Q16-FIND WORKER HAVING "a" IN FIRST_NAME
    -- SELECT * FROM WORKER WHERE FIRST_NAME LIKE '%A%';
      
  -- Q17-FIND WORKER HAVING "a" AS LAST CHARACTER FIRST_NAME
    -- SELECT * FROM WORKER WHERE FIRST_NAME LIKE '%a';
  
      
  -- Q18-FIND WORKER HAVING "a" AS LAST CHARACTER FIRST_NAME AND 6 AS LENGTH
    -- SELECT * FROM WORKER WHERE FIRST_NAME LIKE '%a' AND LENGTH(FIRST_NAME)=6;
      -- OR
    -- SELECT * FROM WORKER WHERE FIRST_NAME LIKE '_____H';
    
  -- Q19-FIND WORKER WHOSE SALARY IS BETWEEN 1 LAKH TO 5 LAKH  
    -- SELECT * FROM WORKER WHERE SALARY BETWEEN 100000 AND 500000;
           
  -- Q20-WORKER WHO JOINED IN FEB 2014
  -- SELECT * FROM WORKER WHERE JOINING_DATE LIKE '2014-02%';
          -- OR  USE A BETTER METHOD
  -- SELECT * FROM WORKER WHERE YEAR(JOINING_DATE)=2014 AND MONTH(JOINING_DATE)=02;
  
  -- Q21-FIND NUMBER OF EMPLOYEE IN ADMIN
    -- SELECT DEPARTMENT ,COUNT(DEPARTMENT) FROM WORKER GROUP BY DEPARTMENT HAVING DEPARTMENT='ADMIN';
      -- OR   WITHOUT USING GROUP BY 
    -- SELECT DEPARTMENT ,COUNT(DEPARTMENT) FROM WORKER WHERE DEPARTMENT='ADMIN';
  -- Q22 FIND FULL NAME WITH SALARY BETWEEN 1LAKH TO 5LAKH
    -- SELECT CONCAT(FIRST_NAME," ",LAST_NAME) AS FULLNAME FROM WORKER WHERE SALARY BETWEEN 100000 AND 500000;
  
  -- Q23-NUMBER OF WORKER IN EACH DEPT IN DESC ORDER
    -- SELECT DEPARTMENT ,COUNT(WORKER_ID) FROM WORKER GROUP BY DEPARTMENT
    -- ORDER BY COUNT(WORKER_ID) DESC;
    
  -- Q24 DETAILS OF WORKER WHO ARE MANAGER
    -- SELECT W.* FROM WORKER AS W INNER JOIN TITLE AS T ON W.WORKER_ID=T.WORKER_REF_ID WHERE WORKER_TITLE='MANAGER';
    
  -- Q25-FETCH NO.(MORE THAN ONE) OF TITLE IN THE ORG OF DIFFERENT TYPES
  -- SELECT WORKER_TITLE,COUNT(WORKER_REF_ID) AS NUMBERS FROM TITLE GROUP BY WORKER_TITLE HAVING COUNT(WORKER_TITLE)>1;
    
  -- Q26-SHOW ONLY ODD ROWS FROM TABLE
    -- SELECT * FROM WORKER WHERE MOD(WORKER_ID,2)!=0;
    --          <>   THIS ALSO WORKS AS != (NOT EQUAL TO)  
    -- SELECT * FROM WORKER WHERE MOD(WORKER_ID,2)<>0;
    
  -- Q27 FIND EVEN
  
  -- Q28-CLONE A NEW TABLE FROM ANOTHER TABLE =>THIS WILL CREATE NEW TABLE SAME SCHEMA AS WORKER
    CREATE TABLE WORKER_CLONE LIKE WORKER ;
    INSERT INTO WORKER_CLONE VALUES(0011,'AABSHAR ','FARID  ',100000,'14-02-20 09.00.00','SOFTWARE ENGINEER');
  
  INSERT INTO WORKER_CLONE SELECT * from WORKER;
  -- this is how we can copy all data from worker to WORKER_CLONE
  
    -- SELECT * FROM WORKER_CLONE;
    
 -- Q-29 FIND INTERSECTING RECORDS OF TWO TABLE WORKER AND TITLE
   -- SELECT WORKER_ID FROM WORKER INNER JOIN WORKER_CLONE USING(WORKER_ID);
   -- AABSHAR IS EXCLUDED HERE BCZ IT IS EXTRA IN WORKER_CLONE;
  
  -- Q-30 FIND RECORDS THAT ARE PRESENT IN ONE BUT NOT IN ANOTHER
  -- USE MINUS USING LEFT JOIN
  -- SELECT *  FROM WORKER_CLONE AS WC   LEFT JOIN WORKER AS W USING(WORKER_ID) WHERE W.WORKER_ID IS NULL;
  
-- Q31-SELECT CURRENT DATE AND timestamp
-- SELECT CURDATE(),CURTIME(),NOW();
 
-- Q-32 SELECT TOP 5 ENTRIES PRSENT IN TABLE AS TOP 5  ORDER BY DESCENDING SALARY
-- SELECT * FROM WORKER WHERE WORKER_ID<6 ORDER BY SALARY DESC;
  -- BUT WHAT IF WE WANT SALARY OF 5 MOST EARNING? SORT THIS IN DESC AND USE LIMIT 5
  -- SELECT * FROM WORKER ORDER BY SALARY DESC LIMIT 5;
 
 
-- Q-33 FIND 5TH HIGHEST SALARY
  -- SELECT SALARY FROM WORKER ORDER BY SALARY DESC LIMIT 4,1;
  --  LIMIT 4,1 MEANS 4 KE BAAD 1 ENTRY BTAO;
  -- LIMIT 4 MEANS 4 ENTRY BTAO;
            -- OR 
  -- SELECT SALARY FROM WORKER AS W1 
  -- WHERE 5=(SELECT COUNT(SALARY) FROM WORKER AS W2 WHERE W1.SALARY<=W2.SALARY );

-- Q-34 detemine 5th highest salalry without using limit keywod
  -- SELECT * FROM WORKER AS W1 
  -- WHERE 4=(SELECT COUNT(DISTINCT W2.SALARY) FROM WORKER AS W2 WHERE W1.SALARY<=W2.SALARY );
  
-- Q-35 FETCH LIST OF EMPLOYEE WITH SAME SALARY
  -- SELECT * FROM WORKER AS W1 INNER JOIN WORKER AS W2 ON W1.SALARY=W2.SALARY WHERE W1.WORKER_ID!=W2.WORKER_ID;
        -- OR WITHOUT USING JOIN KEYWORD
  -- SELECT W1.* FROM WORKER W1,WORKER W2 WHERE W1.SALARY=W2.SALARY AND W1.WORKER_ID!=W2.WORKER_ID;
  
  
-- Q-36 FIND SECOND HIGHTEST SALARY
  -- SELECT   DISTINCT SALARY FROM WORKER ORDER BY SALARY DESC  LIMIT 1,1;
            -- OR USING SUBQUERRY
  -- SELECT MAX(SALARY) FROM WORKER WHERE SALARY NOT IN (SELECT MAX(SALARY) FROM WORKER );

-- Q-37 SKIPPED

-- Q-38LIST WORKER ID WHO DIDN TGET BONUS
  -- SELECT W.WORKER_ID FROM WORKER AS W  LEFT JOIN BONUS AS B ON W.WORKER_ID=B.WORKER_REF_ID WHERE B.WORKER_REF_ID IS NULL;
    -- OR USING SUBQUERRY
  -- SELECT WORKER_ID FROM WORKER WHERE WORKER_ID NOT IN(SELECT WORKER_REF_ID FROM BONUS);  


-- Q-39 FETCH FIRST 50% DATA FROM TABLE
  -- SELECT * FROM WORKER WHERE WORKER_ID <=(SELECT COUNT(WORKER_ID)/2 FROM WORKER);


-- Q-40 FETCH DEPARTMENT THAT HAS LESS THAN 4 PEOPLE INT IT
  -- SELECT DEPARTMENT FROM WORKER GROUP BY DEPARTMENT HAVING COUNT(WORKER_ID)<4;

    
-- Q-41 FETCH DEPARTMENT ALONG WITH NO OF WORKER 
-- SELECT DEPARTMENT,COUNT(WORKER_ID) FROM WORKER GROUP BY DEPARTMENT;

-- Q-42 FETCH LAST ENTRY IN WORKER TABLE
  -- SELECT * FROM WORKER WHERE WORKER_ID=(SELECT MAX(WORKER_ID) FROM WORKER);

-- Q-43 FETCH FIRST ENTRY IN WORKER TABLE
  -- SELECT * FROM WORKER WHERE WORKER_ID=(SELECT MIN(WORKER_ID) FROM WORKER);
   
   
-- Q-44 LAST 5 RECORDS FROM TABLE AND PRINT IN ACTUAL TABLE ORDER
-- (SELECT * FROM WORKER ORDER BY WORKER_ID DESC LIMIT 5) ORDER BY WORKER_ID ASC;

-- Q-45 NAME OF EMPLOYEE HAVING HIGHEST SALARY IN EACH DEPARTMENT
  -- SELECT W.* FROM 
  -- (SELECT MAX(SALARY) AS MAXSAL,DEPARTMENT FROM WORKER GROUP BY DEPARTMENT) TEMP
  -- INNER JOIN WORKER AS W ON W.DEPARTMENT=TEMP.DEPARTMENT AND W.SALARY=TEMP.MAXSAL ;
 
-- Q-46 3 MAX SALARY FROM WORKER USING CORELATED SUBQUERRY
    -- SELECT DISTINCT SALARY FROM WORKER AS W1 
    -- WHERE 3>=(SELECT COUNT(DISTINCT SALARY) FROM WORKER AS W2
    -- WHERE W1.SALARY<=W2.SALARY);
 
-- Q-47 FETCH THREE MIN SALARY FROM WORKER UAING CORELATED SUBQUERRY
    -- SELECT DISTINCT SALARY FROM WORKER AS W1 
    -- WHERE 3>=(SELECT COUNT(DISTINCT SALARY ) FROM WORKER AS W2 
    -- WHERE W1.SALARY>=W2.SALARY);
    
-- Q-48 FETCH 3TH MAX SALARY 
  -- SELECT DISTINCT SALARY FROM WORKER AS W1 
  -- WHERE 3=(SELECT COUNT(DISTINCT SALARY) FROM WORKER AS W2
  -- WHERE W1.SALARY<=W2.SALARY);  

-- Q-49 FETCH TOTAL SALARY ALONG WITH DEPARTMENT THAT GOES IN EACH DEPARTMENT
    -- SELECT DEPARTMENT,sum(SALARY) AS EXP FROM WORKER GROUP BY DEPARTMENT ORDER BY EXP DESC;
    
-- Q-50 NAME OF WORKER WHO EARN MAX SALARY
  -- SELECT FIRST_NAME FROM WORKER WHERE SALARY = (SELECT MAX(SALARY) FROM WORKER);
  --           OR USING CORELATED SUBQUERRY
  -- SELECT FIRST_NAME FROM WORKER AS W1 WHERE
  -- 1>=(SELECT COUNT(DISTINCT SALARY) FROM WORKER AS W2 WHERE 
  -- W1.SALARY<=W2.SALARY);

created 1 year ago by AABSHAR FARID

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;