大约有 41,000 项符合查询结果（耗时：0.0648秒） [XML]
How to return an empty ActiveRecord relation?
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489
There is a now a "correct" mechanism in Rails 4:
>> Model.none
=> #<ActiveRecord...
Is the sizeof(some pointer) always equal to four?
For example:
sizeof(char*) returns 4. As does int* , long long* , everything that I've tried. Are there any exceptions to this?
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Unexpected results when working with very big integers on interpreted languages
...supports arbitrary precision. It will produce the correct answer on 32 or 64 bit platforms.
This can be seen by raising 2 to a power far greater than the bit width of the platform:
>>> 2**99
633825300114114700748351602688L
You can demonstrate (with Python) that the erroneous values you...
Swapping column values in MySQL
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204
I just had to deal with the same and I'll summarize my findings.
The UPDATE table SET X=Y, Y=X...
Changing Vim indentation behavior by file type
...ould indent with 2 spaces, but if I open a Powershell script it should use 4 spaces.
11 Answers
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I need to store postal codes in a database. How big should the column be?
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answered Nov 28 '08 at 4:19
stragerstrager
81.9k2323 gold badges125125 silver badges171171 bronze badges
...
How do you print out a stack trace to the console/log in Cocoa?
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547
NSLog(@"%@",[NSThread callStackSymbols]);
This code works on any thread.
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Which is faster: while(1) or while(2)?
... call __main
.L2:
jmp .L2
.seh_endproc
.ident "GCC: (tdm64-2) 4.8.1"
With -O1:
.file "main.c"
.intel_syntax noprefix
.def __main; .scl 2; .type 32; .endef
.text
.globl main
.def main; .scl 2; .type 32; .endef
.seh_proc main
main...
PHP Regex to check date is in YYYY-MM-DD format
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Try this.
$date="2012-09-12";
if (preg_match("/^[0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|[1-2][0-9]|3[0-1])$/",$date)) {
return true;
} else {
return false;
}
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improve t...
Having both a Created and Last Updated timestamp columns in MySQL 4.0
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edited Apr 21 '14 at 15:19
kingjeffrey
13k55 gold badges3838 silver badges4747 bronze badges
a...