SQL:
  1. Difference between primary key and unique key
  2. Difference between COALESCE and ISNULL
  3.  which is faster subquery or inner join?
  4.  magic tables
  5.  if you have search functionality and your query is slow.  what steps you will follow to optimise your query?
  6.  can we call stored procedure from Trigger or Trigger from stored procedure?
  7.  I have table column VARCHAR(10) and I am passing 15 Char to it. What will happen?
  8. Write Query:
 select rows which are not common in two tables

  1.  what is use of partition by?
  2. What is CTE Table?  can we access it anywhere in stored procedure after declared?
  3.  select any numeric record from table (1,2,3,1A,2B,3c)
  4.  select alternate records
  5.  create copy of a table
  6.  what should be the best data type for primary key?