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Adding a new SQL column with a default value
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Try this:
ALTER TABLE table1 ADD COLUMN foo INT DEFAULT 0;
From the documentation that you linked to:
ALTER [ONLINE | OFFLINE] [IGNORE] TABLE tbl_name
alter_specification [, alter_specification] ...
alter_specification:
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ADD [COLUMN] (col_name column_definition,...)
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Ideal Ruby project structure
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See the following example from http://guides.rubygems.org/what-is-a-gem/
% tree freewill
freewill/
├── bin/
│ └── freewill
├── lib/
│ └── freewill.rb
├── test/
│ └── test_f...
How do I animate constraint changes?
...ateWithDuration:5
animations:^{
self._addBannerDistanceFromBottomConstraint.constant = -32;
[self.view layoutIfNeeded]; // Called on parent view
}];
bannerIsVisible = FALSE;
}
- (void)moveBannerOnScreen {
[self.view layoutIfNeeded];
[UIView anim...
shell init issue when click tab, what's wrong with getcwd?
...ly occurs when your current directory does not exist anymore. Most likely, from another terminal you remove that directory (from within a script or whatever). To get rid of this, in case your current directory was recreated in the meantime, just cd to another (existing) directory and then cd back; t...
When to use thread pool in C#? [closed]
... need to make your IO related tasks concurrently such as downloading stuff from remote servers or disk access, but need to do this say once every few minutes, then make your own threads and kill them once you're finished.
Edit: About some considerations, I use thread pools for database access, phys...
How can i get the session object if i have the entity-manager
...at the result of this method is implementation specific i.e. non portable from application server using Hibernate to the other. For example with JBoss you would do:
org.hibernate.Session session = (Session) manager.getDelegate();
But with GlassFish, you'd have to do:
org.hibernate.Session sessi...
how to calculate binary search complexity
... the input required to search hence it is log(n) algorithm. Since I am not from a mathematics background I am not able to relate to it. Can somebody explain it in a little more detail? does it have to do something with the logarithmic series?
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hash function for string
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There are a number of existing hashtable implementations for C, from the C standard library hcreate/hdestroy/hsearch, to those in the APR and glib, which also provide prebuilt hash functions. I'd highly recommend using those rather than inventing your own hashtable or hash function; they'...
Are there any cases when it's preferable to use a plain old Thread object instead of one of the newe
...use in many cases those are more appropriate as they shield the programmer from needlessly reinventing the wheel, doing stupid mistakes and the like, that does not mean that the Thread class is obsolete. It is still used by the abstractions named above and you would still need it if you need fine-gr...
Why specify @charset “UTF-8”; in your CSS file?
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It is also important if you link those files from non-UTF-8-sites, like, say: a japanese website encoded as UTF-16 trying to load CSS from a CDN will get unreadable content if the CSS file doesn't declare its encoding.
– Paracetamol
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