大约有 43,000 项符合查询结果（耗时：0.0419秒） [XML]
Postgresql GROUP_CONCAT equivalent?
...
This is probably a good starting point (version 8.4+ only):
SELECT id_field, array_agg(value_field1), array_agg(value_field2)
FROM data_table
GROUP BY id_field
array_agg returns an array, but you can CAST that to text and edit as needed (see clarifications, below).
Prior to version 8.4, you...
Integrating the ZXing library directly into my Android application
...t XML file:
<ImageView
android:id="@+id/qrCode"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="50dp"
android:layout_centerHorizontal="true"/>
Code snippet:
// ImageView to display the QR code in. This should be defin...
Eclipse ctrl+right does nothing
... kind of bug in the editor specifically (https://bugs.eclipse.org/bugs/show_bug.cgi?id=426557). Sometimes you can find that when you restart can't move with control+arrow in the editor but you can in other views like console window.
You can disable welcome screen ( in most eclipse based IDEs it's a...
How to create an empty file at the command line in Windows?
...omad mentions an original one:
C:\Users\VonC\prog\tests>aaaa > empty_file
'aaaa' is not recognized as an internal or external command, operable program or batch file.
C:\Users\VonC\prog\tests>dir
Folder C:\Users\VonC\prog\tests
27/11/2013 10:40 <REP> .
27/11/2013 10...
Why do we need C Unions?
...le types together:
enum Type { INTS, FLOATS, DOUBLE };
struct S
{
Type s_type;
union
{
int s_ints[2];
float s_floats[2];
double s_double;
};
};
void do_something(struct S *s)
{
switch(s->s_type)
{
case INTS: // do something with s->s_ints
break;
case F...
Better way to sum a property value in an array
...y.prototype.sum = function (prop) {
var total = 0
for ( var i = 0, _len = this.length; i < _len; i++ ) {
total += this[i][prop]
}
return total
}
console.log(traveler.sum("Amount"))
The Fiddle: http://jsfiddle.net/9BAmj/
...
How can I get `find` to ignore .svn directories?
... -o -path \*/.git -o -path \*/.hg -o -path \*/.bzr \
-o -path \*/_MTN -o -path \*/_darcs -o -path \*/\{arch\} \) \
-prune -o \
\( -name .\#\* -o -name \*.o -o -name \*\~ -o -name \*.bin -o -name \*.lbin \
-o -name \*.so -o -name \*.a -o -name \*.ln -o -name \*.blg \
...
Default parameters with C++ constructors [closed]
...lt parameter workaround unnecessary: en.wikipedia.org/wiki/C%2B%2B11#Object_construction_improvement
– mskfisher
Jun 4 '13 at 18:01
...
How can I avoid running ActiveRecord callbacks?
I have some models that have after_save callbacks. Usually that's fine, but in some situations, like when creating development data, I want to save the models without having the callbacks run. Is there a simple way to do that? Something akin to...
...
Nginx缓存解决方案：SRCache - 更多技术 - 清泛网 - 专注C/C++及内核技术
...。
闲言碎语不多讲，表一表Nginx配置文件长啥样：
lua_shared_dict phoenix_status 100m;
lua_package_path '/path/to/phoenix/include/?.lua;/path/to/phoenix/vendor/?.lua;;';
init_by_lua_file /path/to/phoenix/config.lua;
server {
listen 80;
server_name foo.com;
...