code: public static <T> String getDeleteSQL(T t, List<Object> values) {
  		
  		Table table = DOInfoReader.getTable(t.getClass());
  		List<Field> keyFields = DOInfoReader.getKeyColumns(t.getClass());
  		
  		StringBuilder sql = new StringBuilder();
  		
  		sql.append("DELETE FROM ");
  		sql.append(getTableName(table));
  		
  		List<Object> _values = new ArrayList<Object>();
  		String where = "WHERE " + joinWhereAndGetValue(keyFields, "AND", _values, t);
  		for(Object value : _values) { // 检查key的值是不是null
  			if(value == null) {
  				throw new NullKeyValueException();
  			}
  		}
  		values.addAll(_values);
  		
  		sql.append(autoSetSoftDeleted(where, t.getClass()));
  		
  		return sql.toString();
  	}
docs: 获得硬删除SQL
  @param t
  @param values
  @return