如何从返回引用游标的 Oracle 过程中获得格式良好的结果?
在 MS SQL Server 中，如果我想检查存储过程的结果，我可能会在 Management Studio 中执行以下操作.
In MS SQL Server if I want to check the results from a Stored procedure I might execute the following in Management Studio.
--SQL SERVER WAY
exec sp_GetQuestions('OMG Ponies')
结果窗格中的输出可能如下所示.
The output in the results pane might look like this.
ID Title ViewCount Votes
----- ------------------------------------------------- ---------- --------
2165 Indexed View vs Indexes on Table 491 2
5068 SQL Server equivalent to Oracle’s NULLS FIRST 524 3
1261 Benefits Of Using SQL Ordinal Position Notation? 377 2
(3 row(s) affected)
无需编写循环或 PRINT 语句.
No need to write loops or PRINT statements.
为了在 Oracle 中做同样的事情，我可能会在 SQL Developer 中执行以下匿名块
To do the same thing in Oracle I might execute the following anonymous block in SQL Developer
--ORACLE WAY
DECLARE
OUTPUT MYPACKAGE.refcur_question;
R_OUTPUT MYPACKAGE.r_question;
USER VARCHAR2(20);
BEGIN
dbms_output.enable(10000000);
USER:= 'OMG Ponies';
recordCount := 0;
MYPACKAGE.GETQUESTIONS(p_OUTPUT => OUTPUT,
p_USER=> USER,
) ;
DBMS_OUTPUT.PUT_LINE('ID | Title | ViewCount | Votes' );
LOOP
FETCH OUTPUT
INTO R_OUTPUT;
DBMS_OUTPUT.PUT_LINE(R_OUTPUT.QUESTIONID || '|' || R_OUTPUT.TITLE
'|' || R_OUTPUT.VIEWCOUNT '|' || R_OUTPUT.VOTES);
recordCount := recordCount+1;
EXIT WHEN OUTPUT % NOTFOUND;
END LOOP;
DBMS_OUTPUT.PUT_LINE('Record Count:'||recordCount);
CLOSE OUTPUT;
END;
这个输出像
ID|Title|ViewCount|Votes
2165|Indexed View vs Indexes on Table|491|2
5068|SQL Server equivalent to Oracle’s NULLS FIRST|524|3
1261|Benefits Of Using SQL Ordinal Position Notation?|377|2
Record Count: 3
所以SQL版本有1行，oracle有18行，输出难看.如果有很多列和/或数据是数字，它会加剧.
So the SQL version has 1 line and the oracle has 18 and the output is ugly. Its exacerbated if there are a lot of columns and/or the data is numeric.
令我感到奇怪的是，如果我在 SQL Developer 或 Management Studio 中编写此语句...
What's odd to me about this is that if I write this statement in either SQL Developer or Management studio...
SELECT
ID,
Title,
ViewCount,
Votes
FROM votes where user = 'OMG Ponies'
结果非常相似.这让我觉得我要么错过了一项技术，要么使用了错误的工具.
The results are fairly similar. This makes me feel like I'm either missing a technique or using the wrong tool.
推荐答案
如果 GetQuestions 是一个返回 refcursor 的函数，这似乎是您在 SQL Server 版本中所拥有的，那么您可能能够做这样的事情:
If GetQuestions is a function returning a refcursor, which seems to be what you have in the SQL Server version, then rather you may be able to do something like this:
select * from table(MyPackage.GetQuestions('OMG Ponies'));
或者，如果您在 PL/SQL 块中需要它，那么您可以在游标中使用相同的选择.
Or if you need it in a PL/SQL block then you can use the same select in a cursor.
您也可以让函数生成 dbms_output 语句，以便它们始终可用于调试，尽管这会增加一些开销.
You can also have the function produce the dbms_output statements instead so they're always available for debugging, although that adds a little overhead.
编辑
嗯，不确定是否可以将返回的 refcursor cast() 转换为可用类型，除非您愿意在包外声明自己的类型(以及该类型的表).你可以这样做，只是为了转储结果:
Hmmm, not sure it's possible to cast() the returned refcursor to a usable type, unless you're willing to declare your own type (and a table of that type) outside the package. You can do this though, just to dump the results:
create package mypackage as
function getquestions(user in varchar2) return sys_refcursor;
end mypackage;
/
create package body mypackage as
function getquestions(user in varchar2) return sys_refcursor as
r sys_refcursor;
begin
open r for
/* Whatever your real query is */
select 'Row 1' col1, 'Value 1' col2 from dual
union
select 'Row 2', 'Value 2' from dual
union
select 'Row 3', 'Value 3' from dual;
return r;
end;
end mypackage;
/
var r refcursor;
exec :r := mypackage.getquestions('OMG Ponies');
print r;
并且您可以在另一个过程或函数中使用调用的结果；它只是在 PL/SQL 之外进行，这似乎有点棘手.
And you can use the result of the call in another procedure or function; it's just getting to it outside PL/SQL that seems to be a little tricky.
编辑添加:使用这种方法，如果它是一个程序，您可以做基本相同的事情:
Edited to add: With this approach, if it's a procedure you can do essentially the same thing:
var r refcursor;
exec mypackage.getquestions(:r, 'OMG Ponies');
print r;
相关文章