使用PLSQL对字符串进行排序，plsql字符串排序

使用PLSQL对字符串进行排序，plsql字符串排序

1.建Function程序

CREATE OR REPLACE FUNCTION sort_string(p_string IN VARCHAR2) RETURN VARCHAR2 IS
  TYPE typ_rec IS RECORD(
    letter VARCHAR2(256), --记录字母
    seq    PLS_INTEGER --记录字母出现次数
    );

  TYPE tab_rec IS TABLE OF typ_rec INDEX BY BINARY_INTEGER;
  tabr     tab_rec;
  l_result VARCHAR2(32767);
BEGIN
  FOR i IN 1 .. length(p_string) LOOP
    tabr(ascii(substr(p_string, i, 1))).letter := substr(p_string,
                                                         i,
                                                         1);
    tabr(ascii(substr(p_string, i, 1))).seq := nvl(tabr(ascii(substr(p_string, i, 1))).seq,
                                                   0) + 1;
  END LOOP;

  FOR i IN tabr.first .. tabr.last LOOP
    IF tabr.exists(i) THEN
      l_result := l_result || rpad(tabr(i).letter,
                                   tabr(i).seq,
                                   tabr(i).letter);
    END IF;
  END LOOP;

  RETURN l_result;
END;

2.用法

例子1：

SQL> SELECT sort_string ('43258888') FROM DUAL;
 
SORT_STRING('43258888')
--------------------------------------------------------------------------------
23458888

例子2：

SQL> SELECT sort_string ('klaktkky') FROM DUAL;
 
SORT_STRING('KLAKTKKY')
--------------------------------------------------------------------------------
akkkklty

文本地址：http://blog.csdn.net/sunansheng/article/details/46331485