大约有 47,000 项符合查询结果（耗时：0.0748秒） [XML]
mysql Foreign key constraint is incorrectly formed error
I have two tables, table1 is the parent table with a column ID and table2 with a column IDFromTable1 (not the actual name) when I put a FK on IDFromTable1 to ID in table1 I get the error Foreign key constraint is incorrectly formed error . I would like to delete table 2 record if tab...
Find size of an array in Perl
...
The first and third ways are the same: they evaluate an array in scalar context. I would consider this to be the standard way to get an array's size.
The second way actually returns the last index of the array, which is not (usually) ...
Android List View Drag and Drop sort
...ords in a listview that I want the user to be able to re-sort using a drag and drop method. I have seen this implemented in other apps, but I have not found a tutorial for it. It must be something that others need as well. Can anyone point me to some code for doing this?
...
How can I generate a unique ID in Python? [duplicate]
I need to generate a unique ID based on a random value.
8 Answers
8
...
Using boolean values in C
...e 1
#define false 0
Explanation
Option 1 will work only if you use C99 and it's the "standard way" to do it. Choose this if possible.
Options 2, 3 and 4 will have in practice the same identical behavior. #2 and #3 don't use #defines though, which in my opinion is better.
If you are undecided, ...
Difference between len() and .__len__()?
...y calling an object's __len__ method. __something__ attributes are special and usually more than meets the eye, and generally should not be called directly.
It was decided at some point long ago getting the length of something should be a function and not a method code, reasoning that len(a)'s mean...
Remove last item from array
...
@PrithvirajMitra You want to remove 1 and 0? So the array ==[2] ?
– Anton
Oct 23 '13 at 14:40
3
...
No Multiline Lambda in Python: Why not?
...r syntax constructs in Python. I was thinking about this on the bus today and realized I couldn't think of a single Python construct that multiline lambdas clash with. Given that I know the language pretty well, this surprised me.
...
Basic HTTP authentication with Node and Express 4
...n: 'yourlogin', password: 'yourpassword'} // change this
// parse login and password from headers
const b64auth = (req.headers.authorization || '').split(' ')[1] || ''
const [login, password] = Buffer.from(b64auth, 'base64').toString().split(':')
// Verify login and password are set and co...
What are the best practices for SQLite on Android?
... the best practices when executing queries on an SQLite database within an Android app?
10 Answers
...