CREATE FUNCTION dbo.f_str(in_f_value_id varchar) 
RETURNS varchar(100) 
AS 
re varchar(100) ; 
BEGIN 
    
    re:='' ; 
    SELECT to_char(f_value) 
    into re 
    FROM zte_cmmia_rs_subp_pu 
    WHERE f_value_id=in_f_value_id ; 
    RETURN re ;
END

------解决方案--------------------

CREATE OR REPLACE FUNCTION f_str(xx VARCHAR2)  
RETURN VARCHAR2
AS  
re varchar(100);
CURSOR v_c  IS SELECT f_value  
   FROM zte_cmmia_rs_subp_pu  
   WHERE f_value_id=xx ;
BEGIN  
   FOR i IN v_c  LOOP
       re:=re||';'||i.f_value;
   END LOOP;
   RETURN TRIM(leading ';' FROM re);  
END;
/

引用楼主 banni2003 的帖子:

CREATE FUNCTION dbo.f_str(@f_value_id varchar(10)) 
RETURNS varchar(100) 
AS 
BEGIN 
    DECLARE @re varchar(100) 
    SET @re='' 
    SELECT @re=@re+';'+CAST(f_value as varchar) 
    FROM zte_cmmia_rs_subp_pu 
    WHERE f_value_id=@f_value_id 
    RETURN(STUFF(@re,1,1,'')) 
END