Oracle的几个Function实例
create or replace function str_list2( key_name in varchar2,
                    key  in varchar2,
                    coname in varchar2,
                    tname     in varchar2 )
return varchar2
as
    type rc is ref cursor;
    str    varchar2(4000);
    sep    varchar2(2);
    val    varchar2(4000);
    cur    rc;
begin
    open cur for 'select '||coname||'
                    from '|| tname || '
                    where ' || key_name || ' = '
                using key;
    loop
        fetch cur into val;
        exit when cur%notfound;
        str := str || sep || val;
        sep := ', ';
    end loop;
    close cur;
    return str;
end;



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create or replace function ip_int2string(intip number) return varchar2 is
    /**
     * added by ty
     * IP段整型格式转换为字符串格式
     *
     * 计算结果必须与com.zznode.inms.ipms.util.AlgorithmToolKit中的
     * public static String getStringIp(int intIp)方法的计算结果一致
     */
  Result varchar2(15);
  min_int number;
  temp number;
  temp1 number;
  temp2 number;
  temp3 number;
  temp4 number;
  flag number;
 
begin
  min_int:=-2147483648;
  if intip<min_int or intip>2147483647 then
     raise_application_error(-20020,'[IPMS] Illegal int IP!');
  end if;
 
  if intip<0 then
     temp:=intip-min_int;
     flag:=0;
  else
     temp:=intip;
     flag:=1;
  end if;
 
  temp1:= bitand(floor(temp/(2**24)),255);--右移24位，进行与运算
  temp2:= bitand(floor(temp/(2**16)),255);--右移16位，进行与运算
  temp3:= bitand(floor(temp/(2**8)),255);--右移8位，进行与运算
  temp4:= bitand(temp,255);--进行与运算
 
  if flag=1 then
     temp1:=temp1+128;
  end if;
 
  Result:=temp1||'.'||temp2||'.'||temp3||'.'||temp4;
  dbms_output.put_line(Result);
  return(Result);
 
  exception
      when others then
       raise_application_error(-20020,'[IPMS] Illegal int IP!');
      
end ip_int2string;

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create or replace function ip_string2int(stringip varchar2) return number is
    /**
     * added