Mysql – Result consisted of more than one row in procedure

i confused with this i try not using cursor and same get error so i back using cursor but before this day my query success and can generate but this get error please help me
i already look other question but no solved my problem.

CREATE DEFINER=`root`@`localhost` PROCEDURE `generate_sallary`(IN `e_codeemployee` VARCHAR(45), IN `p_idperiod` INT)  

DECLARE p_startperiod, p_endperiod, a_attendancedate date;
declare a_checkin, a_checkout, s_workstart, s_workend time;
declare c_classid,t_workday , t_worktime, t_offs, t_absents, t_lates, t_overtimes, t_outearly, a_id, a_done, gs_tolerance, gs_sallary_hour, sr_id, chek int;
declare es_sallary, es_sallary_per_day, es_sallary_per_hour, sr_late, sr_absent, sr_outearly, sr_overtime, pr_incomesallary, pr_income_overtime, pr_deduction_absent, pr_deduction_late, pr_deduction_out_early double;
declare a_flag varchar(16);
declare a_cursor cursor for select id FROM attendance WHERE attendance_date between (SELECT start_period FROM period WHERE id = p_idperiod) AND (SELECT end_period FROM period WHERE id = p_idperiod) AND attendance.employee_code = e_codeemployee;
declare continue handler for not found set a_done = TRUE;

set chek = 0;
set gs_tolerance = 15;    
set a_done = 0;
set t_workday = 0;
set t_worktime = 0;
set t_offs = 0;
set t_absents = 0;
set t_lates = 0;
set t_overtimes = 0;
set t_outearly = 0;

select e.class_id into c_classid FROM employees e WHERE e.employee_code = e_codeemployee;
select es.sallary, es.sallary_per_day, es.sallary_per_hour, sr.late, sr.absent, sr.out_early, sr.overtime, sr.id into es_sallary, es_sallary_per_day, es_sallary_per_hour, sr_late, sr_absent, sr_outearly, sr_overtime, sr_id from employee_sallary es join sallary_rules sr on es.sallary_rule_id = sr.id;

open a_cursor;
repeat    
    fetch a_cursor into a_id;   
    if not a_done then
        select a.attendance_date, a.check_in, a.check_out, a.flag, s.work_start, s.work_end into a_attendancedate, a_checkin, a_checkout, a_flag, s_workstart, s_workend from attendance a inner join shift s on a.shift_id = s.id where a.id = a_id ;
        if (a_checkin < s_workstart) then
            set a_checkin = s_workstart;
        end if;
        if (a_checkout = null) OR (a_checkout = '00:00:00') then
            set a_checkout = s_workend;
        end if;
        if (a_flag = 'fulltime') then
            set t_workday = t_workday +1;
        elseif (a_flag = 'partime') then
            set t_worktime = t_worktime + hour(timediff(a_checkin, a_checkout));
            if (minute(timediff(a_checkin, a_checkout)) > gs_tolerance) then
                set t_worktime = t_worktime + 1;
            end if;
        elseif (a_flag = 'absent') then
            set t_absents = t_absents + 1;
        else
            set t_offs = t_offs +1;
        end if;
        if (a_checkin > s_workstart) then
            set t_lates = t_lates + hour(timediff(a_checkin, s_workstart));
            if (minute(timediff(a_checkin, s_workstart)) > gs_tolerance) then
                set t_lates = t_lates + 1;
            end if;
        else
            set t_outearly = t_outearly + hour(timediff(a_checkin, s_workstart));
            if (minute(timediff(a_checkin, s_workstart)) > gs_tolerance) then
                set t_outearly = t_outearly + 1;
            end if;
        end if;

        if (a_checkout > s_workend) then 
            set t_overtimes = t_overtimes + hour(timediff(a_checkout, s_workend));
            if (minute(timediff(a_checkout, s_workend)) > gs_tolerance) then
                set t_overtimes = t_overtimes + 1;
            end if;
        end if;     
    end if;
    until a_done
end repeat;
select p.status into chek FROM payroll p WHERE employee_code = e_codeemployee;
if (chek = 1) then
    DELETE FROM payroll  WHERE employee_code = e_codeemployee;
end if;
set pr_incomesallary = t_workday * es_sallary_per_day;
set pr_incomesallary = pr_incomesallary + (t_worktime * es_sallary_per_hour);
set pr_income_overtime = t_overtimes * sr_overtime;    
set pr_deduction_absent = t_absents * sr_absent;
set pr_deduction_late = t_lates * sr_late;
set pr_deduction_out_early = t_outearly * sr_outearly;
INSERT INTO payroll 
(employee_code, class_id, period_id, sallary, sallary_per_day, sallary_per_hour, rules_id, late, absent, out_early, overtime, t_work_day, t_work_time, t_off, t_absent, t_late, t_overtime, t_out_early, income_overtime,income_sallary, deduction_absent, deduction_late, deduction_out_early)
VALUES
(e_codeemployee, c_classid , p_idperiod,  es_sallary, es_sallary_per_day, es_sallary_per_hour,sr_id ,sr_late, sr_absent, sr_outearly, sr_overtime, t_workday ,t_worktime , t_offs, t_absents, t_lates, t_overtimes, t_outearly,pr_income_overtime, pr_incomesallary ,pr_deduction_absent,pr_deduction_late,pr_deduction_out_early);

END