sql interview quize

# Frequently asked question in interview is ' what is the difference b/w delete,truncate and drop'. DELETE 1. Delete is a DML operation, it can be rollback 2. By using it rows from table can delete. 3. It can used with indexs and views. TRUNCATE 1.  Truncate is a DDL operation, it can not be rollback 2.  By using it all rows from table deleted. 3. It cannot used with indexes and views. DROP 1.  Truncate is a DDL operation, it can not be rollback 2.  By using it whole table delete including the records. 3.  It cannot used with indexes and views.

The question always asked during interview is how to find Nth salary of Employee # Let we consider a table  Employee_Salary  contains the columns  Emp_Id,Emp_Name,Emp_Salary . Employee_Salary   Emp_Name   Emp_Id   Emp_Salary  Rakesh  001  8000  Ashish   002  10000  Shalu   003  11000  Mohit   004  12000  Anurag   005  13000  Bhanu   006  14000 ##  Now we go through N th Salary * SELECT  Top 1 Emp_Salary FROM  (Select  Top Nth   Emp_Salary form  Employee_Salary           order   by  Emp_Salary desc) as EmpSalary order by Emp_Salary   Example #   SELECT   Top 1  Emp_Salary FROM  (Select   Top 3   Emp_Salary form  Employee_Salary  ...

The basic question always asked during interview is how to find second max salary of Employee # Let we consider a table Employee_Salary contains the columns Emp_Id,Emp_Name,Emp_Salary . Employee_Salary   Emp_Name   Emp_Id   Emp_Salary  Rakesh  001  8000  Ashish   002  10000  Shalu   003  11000  Mohit   004  12000  Anurag   005  13000  Bhanu   006  14000 ## So let we go through Max Salary *  SELECT  MAX(Emp_Salary) FROM   Employee_Salary  here we get the max salary of employee from  Employee_Salary   table. ///////ouput is  14000 ## Now we go through Second Max Salary * SELECT  MAX(Emp_Salary) FROM   E...

The beginner should know the basic steps to create the table in sql. CREATE TABLE TABLENAME  ( COMP_CODE    VARCHAR(30), UNIT_CODE        VARCHAR(20), BR_CODE            VARCHAR(20) ) EXPLANATION :- 1-- Here  TABLENAME  is   the name of table  the you want to create. 2-  Here  COMP_CODE    is the name of column in the table. 3 -Here   VARCHAR(30),  is the the data type use for column and 30 show its size. This is the basic step to create table in database, Like that we can create number of tables in database. *Table is basically a database object which consists number of row and column,its appear like    Gride.