20 SQL Query Questions and Answers for Practice

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, '14-06-11 09.00.00', 'Account'),
		(007, 'Satish', 'Kumar', 75000, '14-01-20 09.00.00', 'Account'),
		(008, 'Geetika', 'Chauhan', 90000, '14-04-11 09.00.00', 'Admin');

Q-1. 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;                             

Q-2. Write an SQL query to fetch “FIRST_NAME” from Worker table in upper case.
Select upper(FIRST_NAME) from Worker;
Q-3. Write an SQL query to fetch unique values of DEPARTMENT from Worker table.
Select distinct DEPARTMENT from Worker;
Q-4. Write an SQL query to print the first three characters of  FIRST_NAME from Worker table.
Select substring(FIRST_NAME,1,3) from Worker;
Q-5. 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 that fetches the unique values of DEPARTMENT from Worker table and prints its length.
Select distinct length(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 all Worker details from the Worker table order by FIRST_NAME Ascending.
Select * from Worker order by FIRST_NAME asc;
Write an SQL query to print all Worker details from the Worker table order by FIRST_NAME Ascending and DEPARTMENT Descending.
Select * from Worker order by FIRST_NAME asc,DEPARTMENT 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 details of the Workers whose FIRST_NAME contains ‘a’.
Select * from Worker where FIRST_NAME like '%a%';
 Write an SQL query to print details of the Workers whose FIRST_NAME ends with ‘a’.
Select * from Worker where FIRST_NAME like '%a';
. Write an SQL query to print details of the Workers whose SALARY lies between 100000 and 500000.
Select * from Worker where SALARY between 100000 and 500000;
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;