${if(year)="to_char(sysdate,'yyyy')","to_char(sysdate,'mm')","12"}
如果年$year是今年的话,就取当前月,要不就取12
${if(year=year(today()),month(today()),"12")}
或
${if(year=year(today()),"to_char(sysdate,'mm')","12")}
上面那个月份个位数时前面没有0