title: Change column type in table
body: <p>I have a datatable called deal in Oracle with four columns:<br>
  DealID: (PK) <br>
  LegID <br>
  OrigID <br>
  Description <br></p>
  
  <p>The problem is that if I want to insert a deal with description = A, the attributes LegID and OrigID must be unique, otherwise, there is not problem. How can i make this check? I had thought a trigger after insert. There are more solutions?</p>
  
  <p>Thanks in advance!!</p>