create function bb_getLoanInterest(bill_id_ varchar(32), start_date_ varchar(32), end_date_ varchar(32)) returns decimal(22,2)
begin
  declare accrued_interest DECIMAL(22,2) default 0; #计提利息
  DECLARE real_start_date varchar(32);
  DECLARE temp_date varchar(32);
  DECLARE plan_date_ varchar(32);
  DECLARE year_rate_ DECIMAL(22,6) DEFAULT 0;
  DECLARE temp_rate DECIMAL(22,6) DEFAULT 0;
  DECLARE gtype int DEFAULT 0;
  DECLARE day_flag int DEFAULT 0;
  DECLARE rate_year_days_ int DEFAULT 360;#年计息天数
  DECLARE remcorpus DECIMAL(22,2);
  DECLARE days int DEFAULT 0;
  declare done boolean default false;
  DECLARE outer_cursor CURSOR FOR select tab.plan_date,tab.rate,tab.gtype from (
    select plan_date,0 as rate,0 as gtype from loan_fund_plan
    where bill_id=bill_id_ and plan_date>=start_date_
    and plan_date<=end_date_ and ifnull(corpus,0)>0
    union
    select adjust_date as plan_date,rate_new as rate,1 as gtype from loan_rate_adjust
    where bill_id=bill_id_ and status_='rate_adjust' and mod_reason='his_rate_change'
          and adjust_date>=start_date_ and adjust_date<=end_date_
    union
    select end_date_ as plan_date,0 as rate,0 as gtype from dual) tab order by tab.plan_date;
  DECLARE CONTINUE HANDLER FOR NOT FOUND SET done=TRUE;
	
  set temp_date = start_date_;
      #如果计提利息期间开始时间小于借据放款日期，则以借据放款日期为开始时间
  SELECT GREATEST(start_date_,loan_start_date) INTO real_start_date FROM loan_bill_info WHERE id=bill_id_;
  SET temp_date = real_start_date;
  SELECT tmp.rate_new INTO temp_rate FROM (SELECT t.rate_new FROM
  (SELECT adjust_date,rate_new,create_date FROM loan_rate_adjust WHERE bill_id=bill_id_ AND status_='rate_adjust' AND mod_reason='his_rate_change' AND adjust_date<=real_start_date
  UNION
  SELECT loan_start_date AS adjust_date,rate AS rate_new, create_date FROM loan_bill_info WHERE id=bill_id_
    )t ORDER BY t.adjust_date DESC,t.create_date DESC LIMIT 1) tmp;
  #对计提利息期间按利率变化及本金变化分段
  open outer_cursor;
  myLoop:loop
    FETCH outer_cursor INTO plan_date_,year_rate_,gtype;
    IF done THEN LEAVE myLoop;
    END IF;
    #取年计息天数
    SELECT rate_year_days INTO rate_year_days_ FROM loan_bill_info WHERE id=bill_id_;
    #算头不算尾，第1个分段，时间加一天
    SELECT DATEDIFF(plan_date_,temp_date) + day_flag INTO days FROM DUAL;
    IF days>=0 THEN
    SET day_flag = 0;
    SELECT SUM(IFNULL(corpus,0)) INTO remcorpus FROM loan_fund_plan WHERE bill_id=bill_id_ AND plan_date>=plan_date_;
    SELECT accrued_interest + (days*remcorpus*(temp_rate/100/rate_year_days_)) INTO accrued_interest FROM DUAL;
		IF gtype=1 THEN
		SET temp_rate = year_rate_;
		END IF;
		SET temp_date = plan_date_;
     end if;
  end loop myLoop;
  close outer_cursor;
  set accrued_interest = round(accrued_interest,2);
  RETURN accrued_interest;
end;