消失的联盟 [英] Vanishing Joins
问题描述
我已经使用Access多年了。好几次，我遇到了一个错误
，我将其称为消失的联接。错误。当它发生时，加入
从查询中随机消失。更具体地说，所有联接从
消失至少一个（看似随机的）查询。
我一直认为消失联接错误是一个症状
腐败。当它发生时，我通常会向我的用户提供有关如何从腐败中恢复的建议，以及如何在将来避免它。然而，这并不是很容易解决的问题。有一次，消失的连接
导致我的一个应用程序出现非常糟糕的故障。
由于源查询中的联接消失，报告看起来正确
但包含错误。错误的报告已经使用了一段时间，并且当错误最终被发现时，我失去了作为一个
开发者的可信度。
由于这种经验，我得出结论，消失的联接
bug特别阴险。当错误发生时，数据库会在没有警告的情况下将错误的模式转换为错误的模式，并产生错误和/或可能长时间未被注意的坏b / b $ b b数据。这是一个错误，超过
其他任何一个，这迫使我建议用户Access只是不够好b $ b足够用于某些目的。
虽然它很阴险，但消失的连接错误很少见。
尽管如此，我上周再次遇到它，这就是导致我的原因
现在想一想。为了一劳永逸地处理它，我正在考虑创建一个存储每个查询的SQL哈希的表。
。然后，启动时
，我会验证哈希值。当发生
错误时，这将提供警告，我应该能够将其作为一般解决方案实现
，可以添加到我的所有应用程序中。在我开始工作之前，
然而，我想触及Access社区的基础，看看其他人对这个问题的看法是什么。
因为它曾多次发生在我身上，我认为这是一个很好的已知错误的b
。然而，在搜索之后，我发现只有一个提到它
（ http://access.softwareheadlines.com/...s-in-frontend-
t72397.html）。因此，作为一个现实检查，我想问：是否
其他开发人员知道这个错误？你有不同的想法
关于它我在这里提出的想法吗？并且，最重要的是，有没有人找到一个简单的方法来处理它？<br />
-TC
我敢打赌你打开了Name AutoCorrect。首先要做的事情
是转到工具，选项，常规选项卡，然后关闭它。我怀疑它是什么是杀死（修复？）连接。如果你在任何时候删除其中一个
加入的成员，然后将其替换，Access，在它的无限
智慧，杀死加入时会员被删除，当你重新导入对象时，它不会取代
。
记住，这不是一个错误，它是'' sa功能！
John
TC带来了这个：
我已经使用Access多年了。好几次，我遇到了一个错误
，我将其称为消失的联接。错误。当它发生时，加入
从查询中随机消失。更具体地说，所有联接从
消失至少一个（看似随机的）查询。
我一直认为消失联接错误是一个症状
腐败。当它发生时，我通常会向我的用户提供有关如何从腐败中恢复的建议，以及如何在将来避免它。然而，这并不是很容易解决的问题。有一次，消失的连接
导致我的一个应用程序出现非常糟糕的故障。
由于源查询中的联接消失，报告看起来正确
但包含错误。错误的报告已经使用了一段时间，并且当错误最终被发现时，我失去了作为一个
开发者的可信度。
由于这种经验，我得出结论，消失的联接
bug特别阴险。当错误发生时，数据库会在没有警告的情况下将错误的模式转换为错误的模式，并产生错误和/或可能长时间未被注意的坏b / b $ b b数据。这是一个错误，超过
其他任何一个，这迫使我建议用户Access只是不够好b $ b足够用于某些目的。
虽然它很阴险，但消失的连接错误很少见。
尽管如此，我上周再次遇到它，这就是导致我的原因
现在想一想。为了一劳永逸地处理它，我正在考虑创建一个存储每个查询的SQL哈希的表。
。然后，启动时
，我会验证哈希值。当发生
错误时，这将提供警告，我应该能够将其作为一般解决方案实现
，可以添加到我的所有应用程序中。在我开始工作之前，
然而，我想触及Access社区的基础，看看其他人对这个问题的看法是什么。
因为它曾多次发生在我身上，我认为这是一个很好的已知错误的b
。然而，在搜索之后，我发现只有一个提到它
（ http://access.softwareheadlines.com/...s-in-frontend-
t72397.html）。因此，作为一个现实检查，我想问：是否
其他开发人员知道这个错误？你有不同的想法
关于它我在这里提出的想法吗？而且，最重要的是，
有人找到了一个简单的方法来处理它吗？
-TC
名称自动更正是我的第一个想法。显然，珍妮特坎宁安有同样的想法。您没有指明是否在前端/后端关闭了名称自动更正
选项。
如果打开查询，可能会发生奇怪的事情在设计视图中，后面的
结束不可用。 （Access 2007处理这个问题比旧版本更好
版本。）
-
Allen Browne - 微软MVP。西澳大利亚珀斯
访问用户提示 - http：// allenbrowne .com / tips.html
回复群组，而不是mvps dot org的allenbrowne。
" TC" < go ********* @ yahoo.comwrote in message
news：01 ********************* ************* @ w7g2000h sa.googlegroups.com ...
我已经使用Access多年了。好几次，我遇到了一个错误
，我将其称为消失的联接。错误。当它发生时，加入
从查询中随机消失。更具体地说，所有联接从
消失至少一个（看似随机的）查询。
我一直认为消失联接错误是一个症状
腐败。当它发生时，我通常会向我的用户提供有关如何从腐败中恢复的建议，以及如何在将来避免它。然而，这并不是很容易解决的问题。有一次，消失的连接
导致我的一个应用程序出现非常糟糕的故障。
由于源查询中的联接消失，报告看起来正确
但包含错误。错误的报告已经使用了一段时间，并且当错误最终被发现时，我失去了作为一个
开发者的可信度。
由于这种经验，我得出结论，消失的联接
bug特别阴险。当错误发生时，数据库会在没有警告的情况下将错误的模式转换为错误的模式，并产生错误和/或可能长时间未被注意的坏b / b $ b b数据。这是一个错误，超过
其他任何一个，这迫使我建议用户Access只是不够好b $ b足够用于某些目的。
虽然它很阴险，但消失的连接错误很少见。
尽管如此，我上周再次遇到它，这就是导致我的原因
现在想一想。为了一劳永逸地处理它，我正在考虑创建一个存储每个查询的SQL哈希的表。
。然后，启动时
，我会验证哈希值。当发生
错误时，这将提供警告，我应该能够将其作为一般解决方案实现
，可以添加到我的所有应用程序中。在我开始工作之前，
然而，我想触及Access社区的基础，看看其他人对这个问题的看法是什么。
因为它曾多次发生在我身上，我认为这是一个很好的已知错误的b
。然而，在搜索之后，我发现只有一个提到它
（ http://access.softwareheadlines.com/...s-in-frontend-
t72397.html）。因此，作为一个现实检查，我想问：是否
其他开发人员知道这个错误？你有不同的想法
关于它我在这里提出的想法吗？而且，最重要的是，
有人找到了一个简单的方法来处理它吗？
-TC
" TC" < go ********* @ yahoo.comwrote in message
news：01 ********************* ************* @ w7g2000h sa.googlegroups.com ...
因为它发生在我身上几个我认为这是一个很好的已知错误。
实际上，我们大多数人从来没有遇到过这个问题，而且你的
难度在
找到信息你的问题证明了这一点。
搜索后，我发现只有一个提到它
确切地说，这不是普通和熟练的开发人员在任何类型的常规基础上遇到的问题。
是
其他开发者是否知道这个bug？
我不知道，从来没有遇到过，我们大多数人都是
。
你有不同的想法
关于它我在这里提出的想法？
我在10年多的开发过程中从未遇到过这个问题，而且每个月有大约20,000
的帖子，这将代表2,400,000个帖子，并不是新闻组中通常提到的
。
换句话说，这是一个非常罕见的罕见事件，正常
有能力的人不会（实际上没有！）给出这个问题的第二个想法，或者花了更多的时间然后在这篇文章中用完了。
所以，大多数情况下，如果有人愿意给这个问题一个人，那么很多人会因为在任何类型的重复或常规问题上都没有这个问题基础。
而且，最重要的是，
有人找到了一个简单的方法来处理它吗？
我认为没有人找到办法处理的事情不是
影响
他们。如上所述，关于唯一提出的建议是关闭
track-autoname正确。
我们应该通过标准的故障排除列表
东西。
你呢：
曲目名称自动更正关闭。
是涉及的网络吗？
是您的应用程序多用户
是您的应用程序拆分
您是否向您的用户分发了一个mde？ br />
您是否已安装更新和错误修复以进行访问？
您是否已安装更新和错误修复喷射？
我当然不是建议这样做问题不存在，也没有在这里缺乏技能，但问题是如此罕见的事情
你不可能找到任何人能够如果你有任何问题，请给你一些帮助。
任何人都有问题。
-
Albert D. Kallal（访问MVP）
加拿大艾伯塔省埃德蒙顿
PL ***************** @ msn.com
I''ve used Access for many years. Several times, I''ve encountered a bug
which I refer to as the "Vanishing Joins" bug. When it happens, joins
vanish randomly from queries. More specifically, all joins vanish from
at least one (seemingly random) query.
I''ve always regarded the Vanishing Joins bug as a symptom of
corruption. When it happens, I usually give my users advice on how to
recover from corruption, and how to avoid it in the future. It isn''t
always resolved that easily, however. On one occasion, vanishing joins
were responsible for a very bad failure of one of my applications.
Because of vanishing joins in a source query, a report looked correct
but contained errors. The erroneous report was used for a while, and
when the errors were finally discovered, I lost credibility as a
developer.
Because of that experience, I''ve concluded that the Vanishing Joins
bug is especially insidious. When the bug occurs, the database shifts
into a faulty mode without warning, and produces errors and/or bad
data that may go unnoticed for a long time. It is this bug, more than
any other, which forces me to advise users that Access is simply not
good enough for some purposes.
Although it is insidious, the Vanishing Joins bug is thankfully rare.
Nevertheless, I encountered it again last week, and that''s what led me
to think about it now. To deal with it once and for all, I''m thinking
about creating a table that stores a hash of each query''s SQL. Then,
on startup, I''ll verify the hash. That will provide a warning when the
bug occurs, and I should be able to implement it as a general solution
that can be added to all my applications. Before I start work on it,
however, I want to touch base with the Access community and see what
others think about this issue.
Because it has happened to me several times, I assumed this was a well-
known bug. After searching, however, I found only one mention of it
(http://access.softwareheadlines.com/...s-in-frontend-
t72397.html). As a reality check, therefore, I''d like to ask: Are
other developers aware of the this bug? Do you have different ideas
about it than the ones I''ve presented here? And, most importantly, has
anyone found an easy way to deal with it?
-TC
I would bet that you have Name AutoCorrect turned on. First thing to do
is go to Tools, Options, General Tab, and turn it off. I suspect it is
what is killing (fixing?) the joins. If at any time you delete one of
the members of the join, and then replace it, Access, in it''s infinate
wisdom, kills the join when the member is deleted, and doesn''t replace
it when you reimport the object.
Remember, it''s not a bug, it''s a feature!
John
TC has brought this to us :I''ve used Access for many years. Several times, I''ve encountered a bug
which I refer to as the "Vanishing Joins" bug. When it happens, joins
vanish randomly from queries. More specifically, all joins vanish from
at least one (seemingly random) query.
I''ve always regarded the Vanishing Joins bug as a symptom of
corruption. When it happens, I usually give my users advice on how to
recover from corruption, and how to avoid it in the future. It isn''t
always resolved that easily, however. On one occasion, vanishing joins
were responsible for a very bad failure of one of my applications.
Because of vanishing joins in a source query, a report looked correct
but contained errors. The erroneous report was used for a while, and
when the errors were finally discovered, I lost credibility as a
developer.
Because of that experience, I''ve concluded that the Vanishing Joins
bug is especially insidious. When the bug occurs, the database shifts
into a faulty mode without warning, and produces errors and/or bad
data that may go unnoticed for a long time. It is this bug, more than
any other, which forces me to advise users that Access is simply not
good enough for some purposes.
Although it is insidious, the Vanishing Joins bug is thankfully rare.
Nevertheless, I encountered it again last week, and that''s what led me
to think about it now. To deal with it once and for all, I''m thinking
about creating a table that stores a hash of each query''s SQL. Then,
on startup, I''ll verify the hash. That will provide a warning when the
bug occurs, and I should be able to implement it as a general solution
that can be added to all my applications. Before I start work on it,
however, I want to touch base with the Access community and see what
others think about this issue.
Because it has happened to me several times, I assumed this was a well-
known bug. After searching, however, I found only one mention of it
(http://access.softwareheadlines.com/...s-in-frontend-
t72397.html). As a reality check, therefore, I''d like to ask: Are
other developers aware of the this bug? Do you have different ideas
about it than the ones I''ve presented here? And, most importantly, has
anyone found an easy way to deal with it?
-TC
Name AutoCorrect was my first thought. Clearly Jeannette Cunningham had the
same idea. You did not indicate whether you have the Name AutoCorrect
options turned off in your front end/back end.
Weird things can happen if you open the query in design view while the back
end is not available. (Access 2007 handles this issue better than older
versions do.)
--
Allen Browne - Microsoft MVP. Perth, Western Australia
Tips for Access users - http://allenbrowne.com/tips.html
Reply to group, rather than allenbrowne at mvps dot org.
"TC" <go*********@yahoo.comwrote in message
news:01**********************************@w7g2000h sa.googlegroups.com...I''ve used Access for many years. Several times, I''ve encountered a bug
which I refer to as the "Vanishing Joins" bug. When it happens, joins
vanish randomly from queries. More specifically, all joins vanish from
at least one (seemingly random) query.
I''ve always regarded the Vanishing Joins bug as a symptom of
corruption. When it happens, I usually give my users advice on how to
recover from corruption, and how to avoid it in the future. It isn''t
always resolved that easily, however. On one occasion, vanishing joins
were responsible for a very bad failure of one of my applications.
Because of vanishing joins in a source query, a report looked correct
but contained errors. The erroneous report was used for a while, and
when the errors were finally discovered, I lost credibility as a
developer.
Because of that experience, I''ve concluded that the Vanishing Joins
bug is especially insidious. When the bug occurs, the database shifts
into a faulty mode without warning, and produces errors and/or bad
data that may go unnoticed for a long time. It is this bug, more than
any other, which forces me to advise users that Access is simply not
good enough for some purposes.
Although it is insidious, the Vanishing Joins bug is thankfully rare.
Nevertheless, I encountered it again last week, and that''s what led me
to think about it now. To deal with it once and for all, I''m thinking
about creating a table that stores a hash of each query''s SQL. Then,
on startup, I''ll verify the hash. That will provide a warning when the
bug occurs, and I should be able to implement it as a general solution
that can be added to all my applications. Before I start work on it,
however, I want to touch base with the Access community and see what
others think about this issue.
Because it has happened to me several times, I assumed this was a well-
known bug. After searching, however, I found only one mention of it
(http://access.softwareheadlines.com/...s-in-frontend-
t72397.html). As a reality check, therefore, I''d like to ask: Are
other developers aware of the this bug? Do you have different ideas
about it than the ones I''ve presented here? And, most importantly, has
anyone found an easy way to deal with it?
-TC
"TC" <go*********@yahoo.comwrote in message
news:01**********************************@w7g2000h sa.googlegroups.com...
Because it has happened to me several times, I assumed this was a well-
known bug.Actually, most of us have never encountered this problem, and your
difficulty in
finding info for your problem proves this.
After searching, however, I found only one mention of itExactly, it not a problem that normal and proficient developers encounter on
any type of regular bases.
Are
other developers aware of the this bug?I was not aware of it, and never encountered it, and that is the case for
most of us.
Do you have different ideas
about it than the ones I''ve presented here?I never had the problem in 10+ years of development, and with about 20,000
posts here a month, that would represent 2,400,000 posts, and it is not
normally mentioned in the newsgroups either.
In other words it is such a insignificant rare occurring event that normal
competent people would not (in fact have not!) given this issue a
2nd thought, or spent more time then what has been used up in this post.
So, for the most part few
if anyone would give this issue one hoot because no one really having this
problem on any type of repeating or regular bases.
And, most importantly, has
anyone found an easy way to deal with it?I don''t think anyone found a way to deal with something that is not
effecting
them. As mentioned, about the only suggesting that came up was to turn off
track-autoname correct.
We should perhaps go through the standard list of trouble shooting
things.
do you:
track name autocorrect turned off.
is a network involved?
is your application multi-user
is your application split
do you distribute a mde to your users?
have you installed updates and bugs fixes to access?
have you installed update and bug fixes to jet?
I am certainly not suggesting that this problem don''t exist, nor is there
some lack of skills at play here, but the issue is such a rare occurrence
you not likely to find anyone who can give you help on something that few if
anyone is having a problem with.
--
Albert D. Kallal (Access MVP)
Edmonton, Alberta Canada
pl*****************@msn.com
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