数据集参数${if ， 如何实现判断条件是个变量？
例如：${if(years=(select to_char(sysdate) from dual)," and to_char(pmdsdocdt,'mm-dd') <= to_char(sysdate,'mm-dd') "," ")} 中的 select to_char(sysdate) from dual
或者：${if(years=( to_char(sysdate) )," and to_char(pmdsdocdt,'mm-dd') <= to_char(sysdate,'mm-dd') "," ")} 中的 to_char(sysdate)
但是这样写会出错
