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How to add “on delete cascade” constraints?
... You have to drop the constraint first, then add the correct version. In standard SQL, I believe the easiest way to do this is to
start a transaction,
drop the foreign key,
add a foreign key with on delete cascade, and finally
commit the transaction
Repeat for each foreign key you want to change...
How to say “should_receive” more times in RSpec
...swer below
for 2 times:
Project.should_receive(:find).twice.with(@project).and_return(@project)
for exactly n times:
Project.should_receive(:find).exactly(n).times.with(@project).and_return(@project)
for at least n times:
Project.should_receive(:msg).at_least(n).times.with(@project).and_return(@pr...
Concatenating string and integer in python
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Modern string formatting:
"{} and {}".format("string", 1)
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Compare version numbers without using split function
... @dev_Boston only one exception...just do with these values v1=1.0001 and v2=1.1 .it gives me equal.
– Sankar M
Sep 27 '11 at 11:31
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How can I map True/False to 1/0 in a Pandas DataFrame?
I have a column in python pandas DataFrame that has boolean True/False values, but for further calculations I need 1/0 representation. Is there a quick pandas/numpy way to do that?
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Custom dealloc and ARC (Objective-C)
...ing ARC, you simply do not call [super dealloc] explicitly - the compiler handles it for you (as described in the Clang LLVM ARC document, chapter 7.1.2):
- (void) dealloc
{
[observer unregisterObject:self];
// [super dealloc]; //(provided by the compiler)
}
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Find all files with a filename beginning with a specified string?
I have a directory with roughly 100000 files in it, and I want to perform some function on all files beginning with a specified string, which may match tens of thousands of files.
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difference between socket programming and Http programming
What is the difference between socket programming and Http programming? can anyone help please?
5 Answers
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Copy table without copying data
copies the table foo and duplicates it as a new table called bar .
4 Answers
4
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Scope of sessionStorage and localStorage
I read some documentation on sessionStorage and localStorage, but I don't understand what the scope is: the domain, a specific page?
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