MySQL
Aug 31, 2018 · 2 min read
- How can we show databases in SQL?
Ans. There is an answer in the question itself…..Yes!!
show databases;2. How can we show tables?
Ans. Again, the answer is in the question itself,
show tables use database_name;Ex. —
show tables use student; — here student is my database_name.
3. How to show columns in a table?
Ans. show columns from table_name;For example : create an employee table as table name Employee :

show columns from Employee;Dept_nameEmp_nameSalary
4. Fetch three highest salaried employees from Employee table?
select salary,emp_name from employee group by emp_name order by salary desc limit 3;Remember sql is not a case sensitive.
and in
- MySQL : we use limit
Syntax :
select col_name(s) from table_name where condition limit number;- Sql server : we use TOP
Syntax : select TOP number/percent col_name from table_name where condition;- Oracle : we use ROWNUM≤number;
Syntax : select col_name(s) from table_name where ROWNUM ≤ number;5. Fetch three least salaried employees?
Ans. Similarly we need to fetch in ascending order(by default sql will fetch in asc) rather than in desc.
select emp_name,salary from employee group by emp_name order by salary limit 3;6. Fetch department wise highest salary from employee table?
select dept_name,,max(salary) from employee group by dept_name order by salary desc;7. To remove duplicate values from the table, we use distinct command.
select distinct * from employee;8. SQL Query order of operations
Ans.
1.from and Join’s
2. where
3. group by
4. having
5. select
6. distinct
7. order by
8. limit