大约有 47,000 项符合查询结果（耗时：0.0859秒） [XML]
How can I see the current value of my $PATH variable on OS X?
...to display the PATH variable or you can just execute set or env to display all of your environment variables.
By typing $PATH you tried to run your PATH variable contents as a command name.
Bash displayed the contents of your path any way. Based on your output the following directories will be se...
What's the best way to join on the same table twice?
...a fan of natural keys and this is a great example why. Natural keys, especially things like phone numbers, can change and frequently so. Updating your database when that change happens will be a HUGE, error-prone headache. *
Method 1 as you describe it is your best bet though. It looks a bit terse ...
What makes a SQL statement sargable?
...L optimizer can't use an index on myDate, even if one exists. It will literally have to evaluate this function for every row of the table. Much better to use:
WHERE myDate >= '01-01-2008' AND myDate < '01-01-2009'
Some other examples:
Bad: Select ... WHERE isNull(FullName,'Ed Jones') = 'Ed...
Running a cron job at 2:30 AM everyday
...mmand
Crontab Format:
MIN HOUR DOM MON DOW CMD
Format Meanings and Allowed Value:
MIN Minute field 0 to 59
HOUR Hour field 0 to 23
DOM Day of Month 1-31
MON Month field 1-12
DOW Day Of Week 0-6
CMD Command Any command to be executed.
Restart cro...
Difference between application/x-javascript and text/javascript content types
...itted in HTML 5).
This isn't a problem in HTTP headers as browsers universally (as far as I'm aware) either ignore the HTTP content-type of scripts entirely, or are modern enough to recognise application/javascript.
share
...
Groovy: what's the purpose of “def” in “def x = 0”?
...e bindings for the current script and groovy treats it (mostly) like a globally scoped variable:
x = 1
assert x == 1
assert this.binding.getVariable("x") == 1
Using the def keyword instead does not put the variable in the scripts bindings:
def y = 2
assert y == 2
try {
this.binding.getVari...
Control the size of points in an R scatterplot?
.... I'm making scatterplots with tens of thousands of points and prefer a small, but not too small dot. Basically, I find pch='.' to be too small, but pch=19 to be too fat. Is there something in the middle or some way to scale the dots down somehow?
...
Node.js client for a socket.io server
...ocket.io server running and a matching webpage with a socket.io.js client. All works fine.
5 Answers
...
How to run only one task in ansible playbook?
...e for this reason.
Example:
tasks:
- yum: name={{ item }} state=installed
with_items:
- httpd
- memcached
tags:
- packages
- template: src=templates/src.j2 dest=/etc/foo.conf
tags:
- configuration
If you wanted to just run the “co...
How do I pull my project from github?
...m/articles/fork-a-repo
Take a look at:
https://help.github.com/
It has really useful content
share
|
improve this answer
|
follow
|
...