In this tutorial I going to show you some tricky sql interview queries which is ask in fresher's interviews. These query are very simple and easy, I hope it will help you to crack the SQL Server Interview.
|Sql interview question for freshers|
create database DBTest
--Check all information about any database
exec sp_helpdb @dbname='Test11718'
create table Employee
EID int primary key identity(1,1),
insert into Employee values('Amar',21,5000),('Carry',22,3000),('Deepak',28,2000),('Ram',21,1000),('XYZ',25,4000)
insert into Employee(Name,Age,Salary) values('Simant',25,500)
Rename a table
Rename column name
Add new column
alter table Employee add address varchar(20)
Change the DataType of column
alter table employee alter column address int
But there is one problem a datatype of column can not be changed when it will have data inside it.
It can be changed also when it will have data too but only in case of upcasting ex:- int to varchar.
Drop the column
alter table Employee drop column address
--------------------Some Select Command ask in interview-------------------------
Get all record of table
select * from Employee
Find Maximum Salary
select MAX(EmpSalary) from Employee
Find Minimum Salary
select MIN(EmpSalary) from Employee
Find Avarage Salary
select AVG(EmpSalary) from Employee
How to find Avarage of string(Like name,address)
select AVG(Name) from Employee
No, you can't find the avarage of name because Operand data type varchar is invalid for avg operator.
Count the record of any column, count function naver count the null value
select count(Name) from Employee
Try MIN and MAX function on another place
select MIN(Name) from Employee
select MAX(Name) from Employee
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