clone

Cloning a MySQL database on the same MySql instance

由 天大地大妈咪最大 提交于 2019-11-26 08:44:42
问题 I would like to write a script which copies my current database sitedb1 to sitedb2 on the same mysql database instance. I know I can dump the sitedb1 to a sql script: mysqldump -u root -p sitedb1 >~/db_name.sql and then import it to sitedb2 . Is there an easier way, without dumping the first database to a sql file? 回答1: As the manual says in Copying Databases you can pipe the dump directly into the mysql client: mysqldump db_name | mysql new_db_name If you're using MyISAM you could copy the

Is there a way to clone form field values in jQuery or javascript?

由 為{幸葍}努か 提交于 2019-11-26 08:29:20
问题 jQuery has a clone() function that clones the actual form with no problem, but it doesn\'t preserve any values that have been entered into the form. Is there a way to get around this? Sample code would be much appreciated. 回答1: ran into the same problem, simple solution: // touch all input values $('input:text').each(function() { $(this).attr('value', $(this).val()); }); var clones = $('input:text').clone(); the trick is that this will change the actual 'value' attribute in the DOM tree,

Java: Rationale of the Cloneable interface

由 女生的网名这么多〃 提交于 2019-11-26 08:26:57
问题 Why wasn\'t the .clone() method specified in the java.lang.Cloneable interface ? 回答1: Basically, it's a broken interface. Ken Arnold and Bill Venners discussed it in Java Design Issues. Arnold: If I were to be God at this point, and many people are probably glad I am not, I would say deprecate Cloneable and have a Copyable , because Cloneable has problems. Besides the fact that it's misspelled, Cloneable doesn't contain the clone method. That means you can't test if something is an instance

What's the best way to make a deep copy of a data structure in Perl?

由 房东的猫 提交于 2019-11-26 08:18:11
问题 Given a data structure (e.g. a hash of hashes), what\'s the clean/recommended way to make a deep copy for immediate use? Assume reasonable cases, where the data\'s not particularly large, no complicated cycles exist, and readability/maintainability/etc. are more important than speed at all costs. I know that I can use Storable, Clone, Clone::More, Clone::Fast, Data::Dumper, etc. What\'s the current best practice? 回答1: Clone is much faster than Storable::dclone , but the latter supports more

What is the best way to clone/deep copy a .NET generic Dictionary<string, T>?

由 丶灬走出姿态 提交于 2019-11-26 07:52:17
I've got a generic dictionary Dictionary<string, T> that I would like to essentially make a Clone() of ..any suggestions. Okay, the .NET 2.0 answers: If you don't need to clone the values, you can use the constructor overload to Dictionary which takes an existing IDictionary. (You can specify the comparer as the existing dictionary's comparer, too.) If you do need to clone the values, you can use something like this: public static Dictionary<TKey, TValue> CloneDictionaryCloningValues<TKey, TValue> (Dictionary<TKey, TValue> original) where TValue : ICloneable { Dictionary<TKey, TValue> ret =

Set Git submodule to shallow clone & sparse checkout?

由 只愿长相守 提交于 2019-11-26 07:37:14
问题 Many vendor Objective-C libraries (e.g., facebook-ios-sdk ) instruct you to copy a certain subset of its repo\'s files/dirs into your Xcode project. One problem with this is then you do not know what revision of the vendor code you have. Another is that if you make changes to the vendor code, it\'s not easy to contribute your changes via Git. As a solution, I want to add each vendor library as a Git submodule of my project\'s repo with some extra settings (say, in the .gitmodules file). This

How to clone a Python generator object?

由 爱⌒轻易说出口 提交于 2019-11-26 06:42:51
问题 Consider this scenario: #!/usr/bin/env python # -*- coding: utf-8 -*- import os walk = os.walk(\'/home\') for root, dirs, files in walk: for pathname in dirs+files: print os.path.join(root, pathname) for root, dirs, files in walk: for pathname in dirs+files: print os.path.join(root, pathname) I know that this example is kinda redundant, but you should consider that we need to use the same walk data more than once. I\'ve a benchmark scenario and the use of same walk data is mandatory to get

Copying a Polymorphic object in C++

由 我的梦境 提交于 2019-11-26 05:29:50
问题 I have base-class Base from which is derived Derived1 , Derived2 and Derived3 . I have constructed an instance for one of the the derived classes which I store as Base* a . I now need to make a deep copy of the object which I will store as Base* b . As far as I know, the normal way of copying a class is to use copy constructors and to overload operator= . However since I don\'t know whether a is of type Derived1 , Derived2 or Derived3 , I cannot think of a way of using either the copy

Serials on NFC Tags - truly unique? cloneable?

由 烂漫一生 提交于 2019-11-26 05:25:31
问题 So are NFC tags really UNIQUE from each other, at least in their SERIAL NUMBER ? And can we rely on the fact that no 2 NFC tags can have the same serial number? I\'m highly skeptical about this as there are (and will be more) NFC tags out there and I don\'t think anyone is controlling the serials... The reason I\'m asking is that I\'m developing a key based system using NFC tags. I don\'t need to write to the tags, I basically just need their serial numbers. But I need them to be truly unique

The difference between fork(), vfork(), exec() and clone()

由 若如初见. 提交于 2019-11-26 04:56:55
问题 I was looking to find the difference between these four on Google and I expected there to be a huge amount of information on this, but there really wasn\'t any solid comparison between the four calls. I set about trying to compile a kind of basic at-a-glance look at the differences between these system calls and here\'s what I got. Is all this information correct/am I missing anything important ? Fork : The fork call basically makes a duplicate of the current process, identical in almost
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