anchor.diff:      ;
   
   add_constraint
  -    : ADD (CONSTRAINT add_constraint_name=constraint_name)?
  +    : ADD (CONSTRAINT constraint_name)?
        ( primary_key_clause
        | foreign_key_clause
        | unique_key_clause
  
positive.code: create_table
      : CREATE (GLOBAL TEMPORARY)? TABLE tableview_name 
          ( '(' (','? datatype_null_enable)+
          (',' CONSTRAINT create_table_constraint_name=constraint_name
            ( primary_key_clause
            | foreign_key_clause
            | unique_key_clause
  
negative.code:     ;
  
  references_clause
      : REFERENCES tableview_name paren_column_list
      ;
  
  on_delete_clause
  