當我爲execute immediate
構建動態SQL語句時,我想使用綁定變量而不是字符串連接。爲什麼我不能在execute immediate語句中使用綁定變量?
在下面的示例中,我可以使用綁定變量a
,b
和ret
,但是當我嘗試綁定爲f
,我收到了ORA-06502: PL/SQL: numeric or value error: character to number conversion error
。爲什麼以及我如何綁定f
?
我正在使用11.2.0.1.0。
create or replace function so4fun (
a in number,
b in number,
f in varchar2
) return number as
decl constant varchar2(32767) :=
'declare a constant number := :a; b constant number := :b;';
stmt varchar2(32676);
ret number;
begin
/* This one works: */
stmt := decl || ' begin :result := ' || f || '; end;';
execute immediate stmt using in a, in b, out ret;
/* But why this one doesn't ?
stmt := decl || ' begin :result := :f; end;';
execute immediate stmt using in a, in b, out ret, in f;
This doesn't work either:
stmt := decl || ' tmp number; begin tmp := :f; :result := tmp; end;';
execute immediate stmt using in a, in b, in f, out ret;
Both are giving me ORA-06502: PL/SQL: numeric or value error: character to
number conversion error */
return ret;
end;
/
show errors
/* expected result when a = 1, b = 2 is 1.5 */
select so4fun(1, 2, '(a + b)/b') from dual;
drop function so4fun;
我選擇了Codo的答案,因爲我看到他的答案更加全面和緊湊。不過,我也發現Ray Toal的回答很有用,我也可以從他的回答中總結出我的問題的答案。我希望他們兩個都有很多讚揚! – user272735