大约有 33,000 项符合查询结果（耗时：0.0372秒） [XML]
Simulate CREATE DATABASE IF NOT EXISTS for PostgreSQL?
...an work around it from within psql by executing the DDL statement conditionally:
SELECT 'CREATE DATABASE mydb'
WHERE NOT EXISTS (SELECT FROM pg_database WHERE datname = 'mydb')\gexec
The manual:
\gexec
Sends the current query buffer to the server, then treats each column of each row of the query's...
ImportError: no module named win32api
...m using Python 2.7 and I want to use pywin32-214 on Windows 7 . I installed pywin32-214 by using the msi installer. But when I import win32api in my Python script, it throws the error:
...
How to prevent gcc optimizing some statements in C?
...eeds. This has the advantage of just applying to a single function and not all functions defined in the same file.
Usage example:
void __attribute__((optimize("O0"))) foo(unsigned char data) {
// unmodifiable compiler code
}
...
What is the fastest way to send 100,000 HTTP requests in Python?
...rogram correctly. Has anyone come across a similar problem? I guess generally I need to know how to perform thousands of tasks in Python as fast as possible - I suppose that means 'concurrently'.
...
What does -D_XOPEN_SOURCE do/mean?
...ch one you need (if any) by looking at the man page for each function you call.
For example, man strdup says:
Feature Test Macro Requirements for glibc (see feature_test_macros(7)):
strdup(): _SVID_SOURCE || _BSD_SOURCE || _XOPEN_SOURCE >= 500
strndup(), strdupa(), strndupa():...
Gradient of n colors ranging from color 1 and color 2
... who was not expecting to see an option like "springgreen" or "royalblue". All colors available to use can be returned as a list by running: colors().
– jadki
Oct 9 '18 at 20:54
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Reload the path in PowerShell
If I have an instance of PowerShell ISE running and I install something that modifies the PATH or I modify it in any way outside of PowerShell then I need to restart PowerShell for it to see the updated PATH variable.
...
When and why should I use fragments in Android applications? [duplicate]
...ntiating a fragment manager, adding the fragment transaction, writing the callbacks of the fragment)
Communication between fragments and activities is harder. As @jonney said it, you would need to deal with a parcelable interface to serialize your objects you wish to pass.
So, when deciding to use...
Using NSPredicate to filter an NSArray based on NSDictionary keys
...
It should work - as long as the data variable is actually an array containing a dictionary with the key SPORT
NSArray *data = [NSArray arrayWithObject:[NSMutableDictionary dictionaryWithObject:@"foo" forKey:@"BAR"]];
NSArray *filtered = [data filteredArrayUsingPredicate:[N...
How do you use https / SSL on localhost?
...t, etc.). Note that depending on configuration the site may still automatically start with the URL rather than the SSL URL. You can see the SSL URL - note the port number and replace it in your browser address bar, you should be able to get in and test.
From there you can right click on your projec...