大约有 6,261 项符合查询结果（耗时：0.0282秒） [XML]
PostgreSQL LIKE query performance variations
...en GiST and GIN index
Example query:
SELECT * FROM tbl WHERE col LIKE '%foo%'; -- leading wildcard
SELECT * FROM tbl WHERE col ILIKE '%foo%'; -- works case insensitively as well
Trigrams? What about shorter strings?
Words with less than 3 letters in indexed values still work. The manual:
...
Inserting HTML elements with JavaScript
...chool JavaScript, you could do this:
document.body.innerHTML = '<p id="foo">Some HTML</p>' + document.body.innerHTML;
In response to your comment:
[...] I was interested in declaring the source of a new element's attributes and events, not the innerHTML of an element.
You need t...
How to delete from a text file, all lines that contain a specific string?
...hine (2012 MacBook Air, OS X 10.13.2). Create file: seq -f %f 10000000 >foo.txt. sed d: time sed -i '' '/6543210/d' foo.txt real 0m9.294s. sed !p: time sed -i '' -n '/6543210/!p' foo.txt real 0m13.671s. (For smaller files, the difference is larger.)
– jcsahnwaldt Reinstate M...
g++ undefined reference to typeinfo
...re missing bodies. In your class definition, something like:
virtual void foo();
Should be defined (inline or in a linked source file):
virtual void foo() {}
Or declared pure virtual:
virtual void foo() = 0;
share
...
Compress files while reading data from STDIN
...
Yes, gzip will let you do this. If you simply run gzip > foo.gz, it will compress STDIN to the file foo.gz. You can also pipe data into it, like some_command | gzip > foo.gz.
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Copy folder recursively, excluding some folders
...
EXCLUDE="foo bar blah jah"
DEST=$1
for i in *
do
for x in $EXCLUDE
do
if [ $x != $i ]; then
cp -a $i $DEST
fi
do...
How do you compare structs for equality in C?
...
You may be tempted to use memcmp(&a, &b, sizeof(struct foo)), but it may not work in all situations. The compiler may add alignment buffer space to a structure, and the values found at memory locations lying in the buffer space are not guaranteed to be any particular value.
But,...
Python function attributes - uses and abuses [closed]
... that a certain method should be part of the web service interface)
class Foo(WebService):
@webmethod
def bar(self, arg1, arg2):
...
then I can define
def webmethod(func):
func.is_webmethod = True
return func
Then, when a webservice call arrives, I look up the method, ...
What is the id( ) function used for?
...ory...
This example might help you understand the concept a little more.
foo = 1
bar = foo
baz = bar
fii = 1
print id(foo)
print id(bar)
print id(baz)
print id(fii)
> 1532352
> 1532352
> 1532352
> 1532352
These all point to the same location in memory, which is why their values are...
Bash empty array expansion with `set -u`
...rsion 4.4.19(1)-release (x86_64-pc-linux-gnu)
$ set -u
$ arr=()
$ echo "foo: '${arr[@]}'"
foo: ''
There is a conditional you can use inline to achieve what you want in older versions: Use ${arr[@]+"${arr[@]}"} instead of "${arr[@]}".
$ function args { perl -E'say 0+@ARGV; say "$_: $ARGV[$_]"...