oracle PLS-00201：标识符必须在程序中声明
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PLS-00201: identifier must be declared in Procedure
提问by Minhaj Patel
I have a PL/SQL Procedure code, which runs when it is /, but doesn't runs when it's executed. The error message I get is
我有一个 PL/SQL 过程代码，它在运行时运行/，但在执行时不运行。我得到的错误信息是
SQL> EXECUTE MAXINUM;
BEGIN MAXINUM; END;
*
ERROR at line 1:
ORA-06550: line 1, column 7:
PLS-00201: identifier 'MAXINUM' must be declared
ORA-06550: line 1, column 7:
PL/SQL: Statement ignored
The code which I'm working on is :
我正在处理的代码是：
DECLARE
N NUMBER;
M NUMBER;
O NUMBER;
P NUMBER;
X NUMBER;
PROCEDURE MAXINUM(N IN NUMBER, M IN NUMBER, O IN NUMBER, P IN NUMBER, X OUT NUMBER) IS
BEGIN
IF N>M AND N>O AND N>P THEN
X:=N;
ELSIF M>N AND M>O AND M>P THEN
X:=M;
ELSIF O>N AND O>M AND O>P THEN
X:=O;
ELSIF P>N AND P>M AND P>O THEN
X:=P;
END IF;
END;
BEGIN
N:=&NUMBER;
M:=&NUMBER;
O:=&NUMBER;
P:=&NUMBER;
MAXINUM(N,M,O,P,X);
DBMS_OUTPUT.PUT_LINE('HIGHEST NUMBER = '||X);
END;
/
When it gave the 'identifier error', I tried dropping this procedure I got the error:
当它给出“标识符错误”时，我尝试删除此过程，但出现错误：
SQL> DROP PROCEDURE MAXINUM;
DROP PROCEDURE MAXINUM
*
ERROR at line 1:
ORA-04043: object MAXINUM does not exist
I have so far read this, this, thissolutions and other solutions some what related to this error.
回答by APC
You have written an anonymous block with a local procedure MAXINUM(). This procedure can be called within that block but does not exist outside that block. Consequently you cannot call it independently.
您已经用本地过程编写了一个匿名块MAXINUM()。该过程可以在该块内调用，但在该块外不存在。因此你不能独立调用它。
If you want to use the procedure elsewhere you need to create it as a first class database object:
如果您想在其他地方使用该过程，您需要将其创建为一级数据库对象：
create or replace procedure MAXINUM
(N IN NUMBER, M IN NUMBER, O IN NUMBER, P IN NUMBER, X OUT NUMBER)
is
BEGIN
IF N>M AND N>O AND N>P THEN
X:=N;
ELSIF M>N AND M>O AND M>P THEN
X:=M;
ELSIF O>N AND O>M AND O>P THEN
X:=O;
ELSIF P>N AND P>M AND P>O THEN
X:=P;
END IF;
END;
/
Now you can call it in your code, like this:
现在您可以在代码中调用它，如下所示：
DECLARE
N NUMBER;
M NUMBER;
O NUMBER;
P NUMBER;
X NUMBER;
BEGIN
N:=&NUMBER;
M:=&NUMBER;
O:=&NUMBER;
P:=&NUMBER;
MAXINUM(N,M,O,P,X);
DBMS_OUTPUT.PUT_LINE('HIGHEST NUMBER = '||X);
END;
/
Points to note:
注意事项：
- what happens if a parameter is null?
- what happens if two arguments have the same value?
- the convention would be to declare this as a function and return the highest value instead of setting an OUT parameter.
- 如果参数为空会发生什么？
- 如果两个参数具有相同的值会发生什么？
- 约定是将其声明为函数并返回最高值而不是设置 OUT 参数。
Incidentally I assume you're doing this as an exercise, as it is a re-implementation of an existing Oracle built-in function, greatest().
顺便说一句，我假设您是作为练习来做这件事的，因为它是对现有 Oracle 内置函数greatest().
