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When to use “ON UPDATE CASCADE”
...regularly but I never use "ON UPDATE CASCADE" as I am not so sure in what situation it will be useful.
7 Answers
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JavaScript “new Array(n)” and “Array.prototype.map” weirdness
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It appears that the first example
x = new Array(3);
Creates an array with undefined pointers.
And the second creates an array with pointers to 3 undefined objects, in this case the pointers them self are NOT undefined, on...
Is there ever a time where using a database 1:1 relationship makes sense?
I was thinking the other day on normalization, and it occurred to me, I cannot think of a time where there should be a 1:1 relationship in a database.
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Checking network connection
...the IP addresses for google.com. Change http://216.58.192.142 to whatever site can be expected to respond quickly.
This fixed IP will not map to google.com forever. So this code is
not robust -- it will need constant maintenance to keep it working.
The reason why the code above uses a fixed IP a...
hexadecimal string to byte array in python
...ex String into a byte array so that I can shift each value out and convert it into its proper data type.
8 Answers
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How to append rows to an R data frame
... those vectors, and then, at the end, create your data.frame.
Continuing with Julian's f3 (a preallocated data.frame) as the fastest option so far, defined as:
# pre-allocate space
f3 <- function(n){
df <- data.frame(x = numeric(n), y = character(n), stringsAsFactors = FALSE)
for(i in 1:...
Text blinking jQuery
What is an easy way to make text blinking in jQuery and a way to stop it? Must work for IE, FF and Chrome. Thanks
35 Answer...
What does an underscore in front of an import statement mean?
I saw this example from sqlite3 on GitHub :
4 Answers
4
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Why does this code segfault on 64-bit architecture but work fine on 32-bit?
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The cast to int* masks the fact that without the proper #include the return type of malloc is assumed to be int. IA-64 happens to have sizeof(int) < sizeof(int*) which makes this problem obvious.
(Note also that because of the undefined behaviour it could st...
time.sleep — sleeps thread or process?
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It blocks the thread. If you look in Modules/timemodule.c in the Python source, you'll see that in the call to floatsleep(), the substantive part of the sleep operation is wrapped in a Py_BEGIN_ALLOW_THREADS and Py_END_ALLOW...