函数的返回值 [英] Return Value of a Function
问题描述
我需要从函数返回一行数据。我一直在寻找HTML
文档并且没有发现任何有价值的内容。如果我尝试返回一个类型为
RECORD的变量，我会收到以下错误：
注意：plpgsql：在第0行编译last_log期间出现错误
错误：fmgr_info：函数0：缓存查找失败
我可能还有其他几个错误的函数，所以我真正的问题
是， 我可以返回RECORD类型的值吗？
-
引用：56
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--Patrick Henry
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电子邮件： te *** @ esc1.com
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I need to return a row of data from a function. I''ve been looking the the HTML
docs and have found nothing of value. If I try to return a variable of type
RECORD, I get the following error:
NOTICE: plpgsql: ERROR during compile of last_log near line 0
ERROR: fmgr_info: function 0: cache lookup failed
I may have several other things wrong with this function, so my real question
is, "Can I return a value of type RECORD?"
--
Quote: 56
"Guard with jealous attention the public liberty. Suspect every one who
approaches that jewel. Unfortunately, nothing will preserve it but down-
right force. Whenever you give up that force, you are inevitably ruined."
--Patrick Henry
Work: 1-336-372-6812
Cell: 1-336-363-4719
email: te***@esc1.com
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推荐答案
2004年2月2日星期一14:36，Terry Lee Tucker写道：
On Monday 02 February 2004 14:36, Terry Lee Tucker wrote:
我可能还有其他几个这个函数有问题，所以我真正的问题是，我可以返回类型为RECORD的值吗？
I may have several other things wrong with this function, so my real
question is, "Can I return a value of type RECORD?"
是的，但是你可以它必须对它做任何事情（除非你从另一个函数中调用它是
）。
你可以返回一个SETOF myrowtype只包含一行 -
，这可能就是你所追求的。那么你可以这样做：
SELECT * FROM set_returning_function（1，''a''）;
-
Richard Huxton
Archonet Ltd
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Yes, but you can''t necessarily do anything with it (unless you''re calling it
from another function).
You could return a SETOF myrowtype where the set contains only one row -
that''s probably what you''re after. Then you can do things like:
SELECT * FROM set_returning_function(1,''a'');
--
Richard Huxton
Archonet Ltd
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Terry Lee Tucker< te *** @ esc1.com>写道：
Terry Lee Tucker <te***@esc1.com> writes:
我需要从函数返回一行数据。我一直在寻找HTML
文档，并没有发现任何有价值的内容。如果我尝试返回一个类型为
RECORD的变量，我会收到以下错误：
注意：plpgsql：在第0行编译last_log期间发生错误
错误：fmgr_info：函数0：缓存查找失败
你运行的Postgres版本是什么？我们曾经有过一些错误，
会允许无意义的错误消息出现在角落
的情况下。我不完全确定他们都已经走了。如果你在上面，那么
7.4。*我很想知道你做了什么。
我可能还有其他一些问题，所以这个功能，所以我真正的问题是，我可以返回RECORD类型的值吗？
I need to return a row of data from a function. I''ve been looking the the HTML
docs and have found nothing of value. If I try to return a variable of type
RECORD, I get the following error:
NOTICE: plpgsql: ERROR during compile of last_log near line 0
ERROR: fmgr_info: function 0: cache lookup failed
What Postgres version are you running? We used to have some bugs that
would allow unhelpful error messages like that to emerge in corner
cases. I''m not completely sure that they''re all gone. If you''re on
7.4.* I''d be interested to see exactly what you did.
I may have several other things wrong with this function, so my real question
is, "Can I return a value of type RECORD?"
如果你知道你在做什么。调用查询必须为记录指定一个
结构。
（乔，我找不到使用函数的自包含示例 - 在7.4文档中搜索后返回 -
记录。当然有一个？）
问候，tom lane
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If you know what you''re doing. The calling query has to specify a
structure for the record.
(Joe, I couldn''t find a self-contained example using a function-returning-
record after a bit of searching in the 7.4 docs. Surely there is one?)
regards, tom lane
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Richard Huxton< de*@archonet.com>写道：
Richard Huxton <de*@archonet.com> writes:
你可以返回一个SETOF myrowtype，其中集合只包含一行 -
这可能就是你所追求的。然后你可以做以下事情：
SELECT * FROM set_returning_function（1，''a''）;
You could return a SETOF myrowtype where the set contains only one row -
that''s probably what you''re after. Then you can do things like: SELECT * FROM set_returning_function(1,''a'');
你很困惑SETOF回来了复合类型---实际上它们
是可以单独使用的正交特征。显然，这个领域的文件可以得到改善:-（
问候，汤姆小巷
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You''re confusing SETOF with returning a composite type --- actually they
are orthogonal features that can be used separately. Obviously the docs
could stand to be improved in this area :-(
regards, tom lane
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