title: merge statment in sql
body: <p>MERGE target as T
  USING source as S
  on T.e_id =S.e_id
  when matched
  then update set T.e_Salary=S.e_salary, T.e_age=S.e_age
  when not matched by target
  then insert (e_id,e_name,e_Salary,e_age,e_gender,e_Dept)
  values(S.e_id,S.e_name,S.e_Salary,S.e_age,S.e_gender,S.e_Dept)
  when not matched by source
  then delete</p>
  <p>I TRY THIS CODE BUT IT SHOWS ERRORS WHILE EXECUTING</p>