大约有 43,000 项符合查询结果（耗时：0.0597秒） [XML]
How to merge lists into a list of tuples?
What is the Pythonic approach to achieve the following?
8 Answers
8
...
Create unique constraint with null columns
...
Create two partial indexes:
CREATE UNIQUE INDEX favo_3col_uni_idx ON favorites (user_id, menu_id, recipe_id)
WHERE menu_id IS NOT NULL;
CREATE UNIQUE INDEX favo_2col_uni_idx ON favorites (user_id, recipe_id)
WHERE menu_id IS NULL;
This way,...
Finding the type of an object in C++
I have a class A and another class that inherits from it, B. I am overriding a function that accepts an object of type A as a parameter, so I have to accept an A. However, I later call functions that only B has, so I want to return false and not proceed if the object passed is not of type B.
...
Detect if Android device has Internet connection
I need to tell if my device has Internet connection or not. I found many answers like:
15 Answers
...
Generating all permutations of a given string
What is an elegant way to find all the permutations of a string. E.g. permutation for ba , would be ba and ab , but what about longer string such as abcdefgh ? Is there any Java implementation example?
...
Understanding reference counting with Cocoa and Objective-C
I'm just beginning to have a look at Objective-C and Cocoa with a view to playing with the iPhone SDK. I'm reasonably comfortable with C's malloc and free concept, but Cocoa's references counting scheme has me rather confused. I'm told it's very elegant once you understand it, but I'm just not o...
How to handle WndProc messages in WPF?
In Windows Forms, I'd just override WndProc , and start handling messages as they came in.
9 Answers
...
Number of rows affected by an UPDATE in PL/SQL
I have a PL/SQL function (running on Oracle 10g) in which I update some rows. Is there a way to find out how many rows were affected by the UPDATE? When executing the query manually it tells me how many rows were affected, I want to get that number in PL/SQL.
...
How do I get the AM/PM value from a DateTime?
The code in question is below:
13 Answers
13
...
What does “exec sp_reset_connection” mean in Sql Server Profiler? [duplicate]
Trying to understand what Sql Profiler means by emitting "sp_reset_connection".
3 Answers
...