Oracle存储过程中去掉重复字符串函数

作者:网络 来源:佚名 更新时间:2008-11-17 15:07:54 点击:

  以下函数是本人在编写oracle数据库存储过程时写的函数,觉得该函数通用性较强,因此发表出来供需要的人参考。

  这个函数的功能主要是用于去除给定字符串中重复的字符串.在使用中需要指定字符串的分隔符.示例:

  str := myreplace('13,14,13,444', ',');

  输出:

13,14,444
create or replace function myreplace(oldstr varchar2, sign varchar2) return varchar2 is
 str varchar2(1000);
 currentindex number;
 startindex number;
 endindex number;
 type str_type is table of varchar2(30)
    index by binary_integer;
 arr str_type;
 result varchar2(1000);
begin  
 if oldstr is null then
  return ('');
 end if;
 
 str := oldstr;
 
 currentindex := 0;
 startindex := 0;
 loop
  currentindex := currentindex + 1;
  endindex := instr(str, sign, 1, currentindex);
  if (endindex <= 0) then
   exit;
 end if;
  
 arr(currentindex) := trim(substr(str, startindex + 1, endindex - startindex - 1));
 startindex := endindex;
 end loop;

  取最后一个字符串:

arr(currentindex) := substr(str, startindex + 1, length(str));

  去掉重复出现的字符串:

for i in 1.. currentindex - 1 loop
 for j in i + 1..currentindex loop
  if arr(i) = arr(j) then
   arr(j) := '';
  end if;
 end loop;
 end loop;
 str := '';
 for i in 1..currentindex loop
 if arr(i) is not null then
  str := str || sign || arr(i);

  数组置空:

arr(i) := '';
 end if;
 end loop;

  去掉前面的标识符:

result := substr(str, 2, length(str));
 return(result);
end myreplace;