大约有 40,000 项符合查询结果（耗时：0.0504秒） [XML]
COUNT(*) vs. COUNT(1) vs. COUNT(pk): which is better? [duplicate]
...T(field) or COUNT(*), and stick with it consistently, and if your database allows COUNT(tableHere) or COUNT(tableHere.*), use that.
In short, don't use COUNT(1) for anything. It's a one-trick pony, which rarely does what you want, and in those rare cases is equivalent to count(*)
Use count(*) fo...
Ruby on Rails generates model field:type - what are the options for field:type?
...nother model's ID. I'd look it up myself, but I haven't figured out, among all my Ruby on Rails documentation links, how to find the definitive source.
...
How can I use tabs for indentation in IntelliJ IDEA?
...nvert tabs to spaces, you can chose "To Spaces" from the same place.
For all files
The paths in the other answers were changed a little:
File > Settings... > Editor > Code Style > Java > Tabs and Indents > Use tab character
File > Other Settings > Default Settings... &g...
How can I pretty-print JSON in a shell script?
...ou can use
curl http://my_url/ | python -m json.tool
For convenience in all of these cases you can make an alias:
alias prettyjson='python -m json.tool'
For even more convenience with a bit more typing to get it ready:
prettyjson_s() {
echo "$1" | python -m json.tool
}
prettyjson_f() {...
What is a “cache-friendly” code?
...her end of the memory spectrum (DRAM), the memory is very cheap (i.e. literally millions of times cheaper) but takes hundreds of cycles after a request to receive the data. To bridge this gap between super fast and expensive and super slow and cheap are the cache memories, named L1, L2, L3 in decre...
Android adb “Unable to open sync connection!”
...e-enabling it has worked so far. Hopefully it keeps working! These fixes really seem like silly hacks.. I'm not sure what the underlying problem is.
share
|
improve this answer
|
...
Throw away local commits in Git
...commits ahead of the origin, and not in a good state. I want to get rid of all these commits and start over again.
19 Answe...
Efficiency of Java “Double Brace Initialization”?
...2$8.class
2009/05/27 16:35 2,022 DemoApp2$9.class
These are all classes which were generated when I was making a simple application, and used copious amounts of anonymous inner classes -- each class will be compiled into a separate class file.
The "double brace initialization", as al...
How do I prevent the padding property from changing width or height in CSS?
...
This is pure magic! - It fixes the box model we all know and hate! i.e. makes it work the way intuition suggests it should - rather than the specs - but as far as I know doesn't break any specs either :D This article clarifies it well... stackoverflow.com/questions/779434/...
Overriding a Rails default_scope
...
Short answer: Do not use default_scope unless you really have to. You'll probably be better off with named scopes. With that said, you can use with_exclusive_scope to override the default scope if you need to.
Have a look at this question for more details.
...