anchor.diff:      ;
   
   delete: 
  -    deleteClause 
  -    whereClause? 
  -    orderByClause? 
  -    limitClause?
  +    deleteClause whereClause? orderByClause? limitClause?
       ;
   
   partitionClause 
  
positive.code: import Keyword, MySQLBase, DQLBase, BaseRule, DataType, Symbol;
  
  execute
      : select
      | insert
      | update
      | delete
      ;
  
  fromClause 
  
negative.code:     ;
  
  groupByClause
      : GROUP BY groupByItem (COMMA groupByItem)* (WITH ROLLUP)? havingClause?
      ;
  
  havingClause
  