大约有 48,000 项符合查询结果（耗时：0.0572秒） [XML]
MySQL ON vs USING?
...lid to just say film_id since that would make for an ambiguity:
ERROR 1052 (23000): Column 'film_id' in field list is ambiguous
As for select *, the joining column appears in the result set twice with ON while it appears only once with USING:
mysql> create table t(i int);insert t select 1...
Javascript parseInt() with leading zeros
...
This is because if a number starts with a '0', it's treated as base 8 (octal).
You can force the base by passing the base as the 2nd parameter.
parseInt("09", 10) // 9
According to the docs, the 2nd parameter is optional, but it's not always assumed to be 10, as y...
Reference: Comparing PHP's print and echo
...e should one wish to use print in a conditional expression. Why 1 and not 100? Well in PHP the truthiness of 1 or 100 is the same, i.e. true, whereas 0 in a boolean context equates as a false value. In PHP all non-zero values (positive and negative) are truthy values and this derives from PHP's Per...
SQLite select where empty?
...ere coalesce(some_column, '') = ''
of
where ifnull(length(some_column), 0) = 0
share
|
improve this answer
|
follow
|
...
What is a lambda expression in C++11?
... be writing a whole class just to do something trivial and one off.
In C++03 you might be tempted to write something like the following, to keep the functor local:
void func2(std::vector<int>& v) {
struct {
void operator()(int) {
// do something
}
} f;
std::for_each(...
Vim Configure Line Number Coloring
...erminal to grey. If you are using gVim, you can:
:highlight LineNr guifg=#050505
share
|
improve this answer
|
follow
|
...
How to git clone a specific tag
... |
edited Jul 17 at 10:11
Giszmo
1,32722 gold badges1212 silver badges3737 bronze badges
answered F...
Take the content of a list and append it to another list
...ange(3)
>>> c = range(2)
>>> b.append(a)
>>> b
[0, 1, 2, [0, 1, 2, 3, 4]]
>>> c.extend(a)
>>> c
[0, 1, 0, 1, 2, 3, 4]
Since list.extend() accepts an arbitrary iterable, you can also replace
for line in mylog:
list1.append(line)
by
list1.extend(m...
What's the difference between `1L` and `1`?
...
130
So, @James and @Brian explained what 3L means. But why would you use it?
Most of the time it ma...
Add a fragment to the URL without causing a redirect?
...
170
window.location.hash = 'something';
That is just plain JavaScript.
Your comment...
Hi, wh...