大约有 47,000 项符合查询结果（耗时：0.0448秒） [XML]
Are foreign keys really necessary in a database design?
...
That's a horrible answer FKs genaerally can add extra overhead not improve performance.
– Agile Jedi
Feb 13 '15 at 18:42
...
PHP: Convert any string to UTF-8 without knowing the original character set, or at least try
...t mb_detect_encoding source code in your php distro (somewhere here: ext/mbstring/libmbfl/mbfl/mbfl_ident.c). This function does not work properly at all. For some encodings it even has "return true", lol. Others are in Ctrl+c Ctrl+v functions. That's because you can not detect encoding without some...
Is there an IDictionary implementation that, on missing key, returns the default value instead of th
... to get default value if key is not there in a dictionary.
Dictionary<string, string> colorData = new Dictionary<string, string>();
string color = colorData.GetValueOrDefault("colorId", string.Empty);
share
...
Any reason to prefer getClass() over instanceof when generating .equals()?
...return super.equals(object) when !(object instanceof Dog) but checking the extra fields when it is a Dog instance wouldn't violate symmetry but would violate transitivity)
– Shadow Man
Jul 16 '19 at 0:16
...
What is your favorite C programming trick? [closed]
...re you can write "str[]" as the last member of a struct). you could make a string "object" like this:
struct X {
int len;
char str[1];
};
int n = strlen("hello world");
struct X *string = malloc(sizeof(struct X) + n);
strcpy(string->str, "hello world");
string->len = n;
here, we've...
How to find elements by class
... because then stylelistrow2 will match. Better comment is "why not use string.find() instead of re?"
– FlipMcF
Mar 5 '15 at 11:52
2
...
What does the smiley face “:)” mean in CSS?
...
Just to throw an extra part to this answer. The answer is great and correct, but missing this the fact that this is not best practice. As a general rule, you should do your best to give the best experience in all browsers that your user base ...
Entity Framework rollback and remove bad migration
...e to a specified migration.
SYNTAX
Update-Database [[-Migration] <String>] [-Context <String>] [-Project <String>] [-StartupProject <String>] [<CommonParameters>]
DESCRIPTION
Updates the database to a specified migration.
RELATED LINKS
Script-Migration...
How to manage startActivityForResult on Android?
...COND_ACTIVITY) {
if(resultCode == Activity.RESULT_OK){
String result=data.getStringExtra("result");
}
if (resultCode == Activity.RESULT_CANCELED) {
//Write your code if there's no result
}
}
}//onActivityResult
To implement passing data b...
Output to the same line overwriting previous output?
...nds in a newline (\n) character, but this can be replaced with a different string. In this case, ending the line with a carriage return instead returns the cursor to the start of the current line. Thus, there's no need to import the sys module for this sort of simple usage. print() actually has a nu...