大约有 40,000 项符合查询结果（耗时：0.0385秒） [XML]
How to return result of a SELECT inside a function in PostgreSQL?
... -- potential ambiguity
END
$func$ LANGUAGE plpgsql;
Call:
SELECT * FROM word_frequency(123);
Explanation:
It is much more practical to explicitly define the return type than simply declaring it as record. This way you don't have to provide a column definition list with eve...
How to prevent a background process from being stopped after closing SSH client in Linux
...
I would recommend using GNU Screen. It allows you to disconnect from the server while all of your processes continue to run. I don't know how I lived without it before I knew it existed.
...
How to add column if not exists on PostgreSQL?
...statement:
DO $$
BEGIN
BEGIN
ALTER TABLE <table_name> ADD COLUMN <column_name> <column_type>;
EXCEPTION
WHEN duplicate_column THEN RAISE NOTICE 'column <column_name> already exists in <table_name>.';
END;
END;
$$
...
Will Emacs make me a better programmer? [closed]
... who are merely good or competent will pick up an IDE and get to know it really well, and maybe do decently enough in it, but they'll restrict themselves to what the IDE provides for them. In other words, they adapt themselves to the IDE. The great programmers, on the other hand, will adapt their en...
How do I run msbuild from the command line using Windows SDK 7.1?
I'm setting up .NET 4.0 support on our CI server. I've installed .NET 4.0, and the .NET tools from the Windows 7.1 SDK.
7 A...
How do I create delegates in Objective-C?
...ign it as the web view's delegate:
MyClass *instanceOfMyClass = [[MyClass alloc] init];
myWebView.delegate = instanceOfMyClass;
On the UIWebView side, it probably has code similar to this to see if the delegate responds to the webViewDidStartLoad: message using respondsToSelector: and send it if ...
C# code to validate email address
...e-mail addresses are more forgiving than you might first assume. These are all perfectly valid forms:
cog@wheel
"cogwheel the orange"@example.com
123@$.xyz
For most use cases, a false "invalid" is much worse for your users and future proofing than a false "valid". Here's an article that used to ...
How do Python functions handle the types of the parameters that you pass in?
...object has a type, every object knows its type, it's impossible to accidentally or deliberately use an object of a type "as if" it was an object of a different type, and all elementary operations on the object are delegated to its type.
This has nothing to do with names. A name in Python doesn't "...
Which way is best for creating an object in JavaScript? Is `var` necessary before an object property
...your example, Person (you should start the name with a capital letter) is called the constructor function. This is similar to classes in other OO languages.
Use way 2 if you only need one object of a kind (like a singleton). If you want this object to inherit from another one, then you have to use a...
Printing a variable memory address in swift
...er was quite old. Many of the methods it describes no longer work. Specifically .core cannot be accessed anymore.
However @drew's answer is correct and simple:
This is now part of the standard library: unsafeAddressOf.
So the answer to your questions is:
println(" str value \(str) has addre...