大约有 40,000 项符合查询结果（耗时：0.0393秒） [XML]
Get names of all keys in the collection
...You could do this with MapReduce:
mr = db.runCommand({
"mapreduce" : "my_collection",
"map" : function() {
for (var key in this) { emit(key, null); }
},
"reduce" : function(key, stuff) { return null; },
"out": "my_collection" + "_keys"
})
Then run distinct on the resulting collecti...
What is the difference between char, nchar, varchar, and nvarchar in SQL Server?
...on as illustrated below.
DECLARE @T TABLE
(
C1 VARCHAR(20) COLLATE Chinese_Traditional_Stroke_Order_100_CS_AS_KS_WS,
C2 NVARCHAR(20)COLLATE Chinese_Traditional_Stroke_Order_100_CS_AS_KS_WS
)
INSERT INTO @T
VALUES (N'中华人民共和国',N'中华人民共和国'),
(N'abc',N'abc')...
How do I install cURL on cygwin?
...
How to install the lynx .
– qg_java_17137
Aug 21 '18 at 7:11
Not working for me. It did some pr...
“Keep Me Logged In” - the best approach
...to page within the app. In this specific application, I'm storing the user_id , first_name and last_name of the person.
...
Using node.js as a simple web server
... Explorer
reg.exe add HKCR\Directory\shell\LightServer\command /ve /t REG_EXPAND_SZ /f /d "\"C:\nodejs\light-server.cmd\" \"-o\" \"-s\" \"%V\""
Simple JSON REST server
If you need to create a simple REST server for a prototype project then json-server might be what you're looking for.
Auto Ref...
Is it better in C++ to pass by value or pass by constant reference?
...r iterators and for function objects (lambdas, classes deriving from std::*_function).
This was especially true before the existence of move semantics. The reason is simple: if you passed by value, a copy of the object had to be made and, except for very small objects, this is always more expensive...
Unique fields that allow nulls in Django
...pty string by providing your own customized model form for Foo with a clean_bar method that turns the empty string into None:
class FooForm(forms.ModelForm):
class Meta:
model = Foo
def clean_bar(self):
return self.cleaned_data['bar'] or None
class FooAdmin(admin.ModelAdmin...
How to import CSV file data into a PostgreSQL table?
...rticle.
Solution paraphrased here:
Create your table:
CREATE TABLE zip_codes
(ZIP char(5), LATITUDE double precision, LONGITUDE double precision,
CITY varchar, STATE char(2), COUNTY varchar, ZIP_CLASS varchar);
Copy data from your CSV file to the table:
COPY zip_codes FROM '/path/to/csv/ZI...
Java ByteBuffer to String
...sibling getBytes() method:
byte[] bytes = k.getBytes( StandardCharsets.UTF_8 );
To put bytes with a particular encoding into a String, you can use a different String constructor:
String v = new String( bytes, StandardCharsets.UTF_8 );
Note that ByteBuffer.array() is an optional operation. If y...
Is there any way to post events to Google Analytics via server-side API? [closed]
... $aParams['qt'] = 0;
//Client ID
$aParams['cid'] = substr(md5($_SERVER['REMOTE_ADDR'].$_SERVER['HTTP_USER_AGENT']), 0, 8);
//User ID
//$aParams['uid'] = '';
//Session Control
//$aParams[''] = '';
//IP Override
$aParams['uip'] = $_SERVER['REMOTE_ADDR'];
//U...