大约有 47,000 项符合查询结果（耗时：0.0485秒） [XML]
Declaring an enum within a class
...uct Color
{
enum Type
{
Red, Green, Black
};
Type t_;
Color(Type t) : t_(t) {}
operator Type () const {return t_;}
private:
//prevent automatic conversion for any other built-in types such as bool, int, etc
template<typename T>
operator T () const;
};
...
Random record from MongoDB
...
Do a count of all records, generate a random number between 0 and the count, and then do:
db.yourCollection.find().limit(-1).skip(yourRandomNumber).next()
share
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How do you run a SQL Server query from PowerShell?
... would use the following. It is what we use at my company.
$ServerName = "_ServerName_"
$DatabaseName = "_DatabaseName_"
$Query = "SELECT * FROM Table WHERE Column = ''"
#Timeout parameters
$QueryTimeout = 120
$ConnectionTimeout = 30
#Action of connecting to the Database and executing the query a...
GitHub clone from pull request?
...sing the -b option and for pull request:
git clone https://github.com/user_name/repo_name.git -b feature/pull_request_name dir_name
In your case, the branch you want to clone is the source branch of the pull request (feature/mongoose-support):
git clone https://github.com/berstend/frappe.git -b ...
SQL select join: is it possible to prefix all columns as 'prefix.*'?
...e is to assign a dummy column to separate each new table. This works especially well if you're looping through a result set for a list of columns in a scripting language such as Python or PHP.
SELECT '' as table1_dummy, table1.*, '' as table2_dummy, table2.*, '' as table3_dummy, table3.* FROM table...
Disable developer mode extensions pop up in Chrome
... to chrome://extensions, check Developer mode and click Pack extension
Install the extension by dragging and dropping the .crx file into the chrome://extensions page.
You'll get an "Unsupported extensions disabled" popup if you try restarting Chrome at this point.
Then for Windows 7 or Windows 8:...
jQuery $.ajax(), $.post sending “OPTIONS” as REQUEST_METHOD in Firefox
... the OPTIONS request and then immediately after that the POST/GET
def send_data(request):
if request.method == "OPTIONS":
response = HttpResponse()
response['Access-Control-Allow-Origin'] = '*'
response['Access-Control-Allow-Methods'] = 'POST, GET, OPTIONS'
resp...
When and why to 'return false' in JavaScript?
...s, such as onsubmit, returning false is a way to tell the event to not actually fire. So, say, in the onsubmit case, this would mean that the form is not submitted.
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How can I perform a `git pull` without re-entering my SSH password?
...use the key!
Neither do I! Thankfully, there’s a nifty little tool called
ssh-agent that can save your passphrase securely so you don’t have
to re-enter it. If you’re on OSX Leopard or later your keys can be
saved in the system’s keychain to make your life even easier. Most
linu...
What is the “N+1 selects problem” in ORM (Object-Relational Mapping)?
The "N+1 selects problem" is generally stated as a problem in Object-Relational mapping (ORM) discussions, and I understand that it has something to do with having to make a lot of database queries for something that seems simple in the object world.
...