以下函數(shù)是本人在編寫Oracle數(shù)據(jù)庫存儲過程時寫的函數(shù),覺得該函數(shù)通用性較強,因此發(fā)表出來供需要的人參考.
這個函數(shù)的功能主要是用于去除給定字符串中重復的字符串.在使用中需要指定字符串的分隔符.示例:
                                                                                            str := MyReplace('13,14,13,444', ',');
輸出:
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;
  
  --取最后一個字符串
  arr(currentIndex) := substr(str, startIndex + 1, length(str));
  
  --去掉重復出現(xiàn)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);
    
    --數(shù)組置空
    arr(i) := '';
  end if;
  end loop;
  
  --去掉前面的標識符
  Result := substr(str, 2, length(str));
  return(Result);
end MyReplace;