oracle 函数写法 总结

1：首先看创建一个函数

给定一个日期,判断是否是休息日.

 create or replace function test(date_in in date)
     return int
 is
     num int;
     workflag varchar2(1);
 begin
     select count(*) into num from Sys_Holiday
         where to_char(TODAY,'yyyy-MM-dd')=to_char(date_in,'yyyy-MM-dd');

     if (num>0) then
         select WORKFLAG into workflag from Sys_Holiday
             where to_char(TODAY,'yyyy-MM-dd')=to_char(date_in,'yyyy-MM-dd');
         if (workflag='W') then
             return 0;
         else
             return 1;
         end if;
     else
         select to_char(date_in,'D') into num from dual;
         if (num=7 or num=1) then
             return 1;
         else
             return 0;
         end if;
     end if;
 end;

2：另外一个函数调用这个函数,一个日期增加或减少多少天对应的日期(工作日)

 CREATE OR REPLACE FUNCTION getWorkDayADD( datetime in date,workday in int) return date
 is
     dayflag int; --初始值,写循环
     sumflag int; --判断值
     datetime1 date;
     workday1  int;
     sysdateadd date;
     daynum    int;
     sysdatelast date; --返回值
 begin
     datetime1 :=datetime;
     workday1 := workday;
     dayflag :=0;
     sumflag :=1;
     if(workday1>0) --加减多少来决定
         then
             while (sumflag=workday1) loop
                  dayflag := dayflag+1;
                  select datetime1+dayflag into sysdateadd from dual;
                  daynum :=test(sysdateadd);
                        if(daynum=1)then
                          sumflag :=sumflag;
                        else
                          sumflag :=sumflag+1;
                        end if;
             end loop;
          else
              while (sumflag=workday1) loop
                    dayflag := dayflag+1;
                  select datetime1-dayflag into sysdateadd from dual;
                  daynum :=test(sysdateadd);
                        if(daynum=1)then
                          sumflag :=sumflag;
                        else
                          sumflag :=sumflag+1;
                        end if;
               end loop;

       end if;
   if(workday1>0) then
         select datetime1+dayflag into sysdatelast  from dual;
        else
         select datetime1-dayflag into sysdatelast  from dual;
     end if;       

   return (sysdatelast);
 end getWorkDayADD;

3 编写一个简单的存储过程调用以上的函数

 create or replace procedure x is
   c date;
   datetime date;
   begin
     select sysdate into datetime from dual;
     dbms_output.put_line(datetime);
     dbms_output.put_line('');
    c := getWorkDayADD(datetime,3);
    dbms_output.put_line(c);
    end;

4 执行存储过程

sql>exec x;