anchor.diff:  onlyClause_
       : ONLY?
       ;
  +
  +tableExistClause_
  +    : (IF EXISTS)?
  +    ;
  +
  +asteriskClause_
  +    : ASTERISK_?
  +    ;
  +
   
   
   
  
positive.code:     : IDENTIFIER_
      ;
  
  alterTableNameExists
      : ALTER TABLE (IF EXISTS)? tableName
      ;
  
  renameTableSpecification_
      : RENAME TO newTableName
      ;
  
negative.code:     ;
  
  alterTable
      : ALTER TABLE tableExistClause_ onlyClause_ tableName asteriskClause_ (alterTableActions | renameColumnSpecification | renameConstraint | renameTableSpecification_)
      ;
  
  alterIndex
  