获取下次要插入的准考证号码
    create or replace function njutec_getNextZkzCode(examyear in varchar2, sourcetype in varchar2,zyid in varchar2) return varchar2 is 
    Result varchar2(100); 
    pre_param01 varchar2(100); 
    pre_param02 varchar2(100); 
    ab varchar2(100); 
    cd integer; 
begin 
    Result:=''; 
    pre_param01:=substr(examyear,3,4)||sourcetype||zyid||'00001'; 
    pre_param02:=substr(examyear,3,4)||sourcetype||zyid||'_____'; 
    select count(*) into cd from LTS_EXAM_SIGNUP where zkzcode = pre_param01; 
   if cd = '0' then 
     Result:=pre_param01; 
   end if; 
   if cd !='0' then 
     select max(zkzcode)+1 into ab from LTS_EXAM_SIGNUP where zkzcode like pre_param02; 
     Result:=ab; 
   end if; 
  return(Result); 
end njutec_getNextZkzCode;