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MySQL Removing Some Foreign keys
...he foreign key constraint has to be dropped by constraint name and not the index name. The syntax is:
alter table footable drop foreign key fooconstraint
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Which CheckedListBox event triggers after a item is checked?
...= CheckState.Checked)
checkedItems.Add(checkedListBox1.Items[e.Index].ToString());
else
checkedItems.Remove(checkedListBox1.Items[e.Index].ToString());
foreach (string item in checkedItems)
{
...
}
}
As another example, to de...
open() in Python does not create a file if it doesn't exist
...losed at the block's end, even if an exception is raised on the way. It's equivalent to try-finally, but much shorter.
with open("file.dat","a+") as f:
f.write(...)
...
a+ Opens a file for both appending and reading. The file pointer is
at the end of the file if the file exists. The ...
Converting RGB to grayscale/intensity
...ixel
unsigned int fourBytes;
unsigned char r,g,b;
for (int index=0;index<width*height;index++)
{
fourBytes=pntrBWImage[index];//caches 4 bytes at a time
r=(fourBytes>>16);
g=(fourBytes>>8);
b=fourBytes;
...
What is the Simplest Way to Reverse an ArrayList?
...n't need to be updated with each iteration. It is initialized to the last index of the ArrayList and is used to access the last element. Inside the for loop the last element is removed and inserted into index i; i is incremented until it reaches the next to last position in the ArrayList.
...
How to set up a PostgreSQL database in Django
...TABASES = {
'default': {
'ENGINE': 'django.db.backends.postgresql',
'NAME': 'db_name',
'USER': 'db_user',
'PASSWORD': 'db_user_password',
'HOST': '',
'PORT': 'db_port_number',
}
}
- Other installation instructions can ...
How do I pass multiple parameters in Objective-C?
...For example, if you are adding an object to an NSMutableArray at a certain index, you would do it using the method:
- (void)insertObject:(id)anObject atIndex:(NSUInteger)index;
This method is called insertObject:atIndex: and it is clear that an object is being inserted at a specified index.
In p...
Force R not to use exponential notation (e.g. e+10)?
...the appropriate notes. It can be confusing to someone who is looking for a quick solution (and Google shows the first one as the result).
– xbsd
Feb 11 '19 at 21:51
add a comm...
Why is sizeof considered an operator?
...
Because the C standard says so, and it gets the only vote.
As consequences:
The operand of sizeof can be a parenthesised type, sizeof (int), instead of an object expression.
The parentheses are unnecessary: int a; printf("%d\n", sizeof a); is perfectly fine. They're often seen, firstly bec...
How to reload/refresh an element(image) in jQuery
...ssible to reload an image with an identical file name from a server using jQuery?
12 Answers
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