anchor.diff:  T_PLAN: P L A N;
   T_FOR: F O R;
   T_INDEX: I N D E X;
  -T_ADD: A D D;
   T_LIST: L I S T;
   T_REMOVE: R E M O V E;
  -T_USING: U S I N G;
   T_UDF: U D F;
   T_PROCESS: P R O C E S S;
   T_TRIGGER: T R I G G E R;
  
positive.code:             {prop=4;}
      )
      {$altast = new AlterTableStatement($name_table.text,$column.text,$type.text,option,prop);  }
  
  selectStatement returns [SelectStatement slctst]:
      T_SELECT {$slctst = new SelectStatement();}
  
negative.code:         LinkedHashMap<String, ValueProperty> option = new LinkedHashMap<>();
          int prop= 0;
      }:
      T_ALTER
      T_TABLE
      name_table=T_IDENT
  