title: DDL commands are AutoCommit in SQL server, what does it mean?
body: <p>at most pages I have read that "DDL commands have AutoCommit in SQL Server", if I am not wrong this statement simply means that we don't need explicit commit command for DDL commands.</p>
  
  <p>then why...</p>
  
  <p>1) Alter TABLE EMP Add Age INT;<br/>
  UPDATE EMP SET Age=20;</p>
  
  <p>fails ,saying Invalid column name 'Age'</p>
  
  <p>2) BEGIN TRAN<br/>
   Alter TABLE EMP Add Age INT;<br/>
  ROLLBACK<br/></p>
  
  <p>can be rollbacked successfully.</p>
  
  <p>Maybe I am wrong with concept of AutoCommit, please explain it with example where it actully has effects.</p>
  
  <p>Thanks for any help.</p>