大约有 48,000 项符合查询结果（耗时：0.0439秒） [XML]
SQL join: selecting the last records in a one-to-many relationship
Suppose I have a table of customers and a table of purchases. Each purchase belongs to one customer. I want to get a list of all customers along with their last purchase in one SELECT statement. What is the best practice? Any advice on building indexes?
...
'App not Installed' Error on Android
I have a program working in the Android Emulator. Every now and again I have been creating a signed .apk and exporting it to my HTC Desire to test. It has all been fine.
...
What SOAP client libraries exist for Python, and where is the documentation for them? [closed]
I've never used SOAP before and I'm sort of new to Python. I'm doing this to get myself acquainted with both technologies. I've installed SOAPlib and I've tried to read their Client documentation, but I don't understand it too well. Is there anything else I can look into which is more suite...
Best practices for catching and re-throwing .NET exceptions
What are the best practices to consider when catching exceptions and re-throwing them? I want to make sure that the Exception object's InnerException and stack trace are preserved. Is there a difference between the following code blocks in the way they handle this?
...
Blocks and yields in Ruby
I am trying to understand blocks and yield and how they work in Ruby.
10 Answers
10
...
PostgreSQL Crosstab Query
... , status text
, ct integer -- "count" is a reserved word in standard SQL
);
INSERT INTO tbl VALUES
('A', 'Active', 1), ('A', 'Inactive', 2)
, ('B', 'Active', 4), ('B', 'Inactive', 5)
, ('C', 'Inactive', 7); -- ('C', 'Active') is missing
Simple form - not fit f...
Definition of a Balanced Tree
... tree for me. I have that "a tree is balanced if each sub-tree is balanced and the height of the two sub-trees differ by at most one.
...
What is Activity.finish() method doing exactly?
I'm developing android applications for a while, and followed a lot of posts about activity life cycle, and application's life cycle.
...
How do I type using my keyboard on the iphone simulator?
...esponding to keystrokes, this fixed it.
Quit the simulator.
Go to finder and press (command+shift+G) then navigate ~/Library/Preferences.
Move com.apple.iphonesimulator.plist to the trash.
Try launching your iPhone app in the simulator again.
...
urlencode vs rawurlencode?
...RL using a variable I have two choices to encode the string. urlencode() and rawurlencode() .
11 Answers
...