大约有 48,000 项符合查询结果（耗时：0.0424秒） [XML]
How to read the database table name of a Model instance?
...
Found the answer myself: the _meta attribute of an instance has the information:
model_instance._meta.db_table
share
|
improve this answer
|
...
Entity Framework - Invalid Column Name '*_ID"
...er I figured my problem out). If you have some error related to OtherTable_ID when you are retrieving Table, go to your OtherTable model and make sure you don't have an ICollection<Table> in there. Without a relationship defined, the framework will auto-assume that you must have a FK to Othe...
Why does the MongoDB Java driver use a random number generator in a conditional?
... laws it is a trivial observation that this piece of code amounts to
if (!_ok && Math.random() <= 0.1)
return res;
The commit that originally introduced this logic had
if (_ok == true) {
_logger.log( Level.WARNING , "Server seen down: " + _addr, e );
} else if (Math.random() < 0...
What kind of leaks does automatic reference counting in Objective-C not prevent or minimize?
...chain referring back to an earlier object.
It is for this reason that the __unsafe_unretained and __weak ownership qualifiers exist. The former will not retain any object it points to, but leaves open the possibility of that object going away and it pointing to bad memory, whereas the latter doesn...
How to convert Strings to and from UTF8 byte arrays in Java
...]:
String s = "some text here";
byte[] b = s.getBytes(StandardCharsets.UTF_8);
Convert from byte[] to String:
byte[] b = {(byte) 99, (byte)97, (byte)116};
String s = new String(b, StandardCharsets.US_ASCII);
You should, of course, use the correct encoding name. My examples used US-ASCII and UT...
Vim delete blank lines
...swered Apr 1 '09 at 15:35
nearly_lunchtimenearly_lunchtime
11k1414 gold badges3434 silver badges4040 bronze badges
...
Python 3 ImportError: No module named 'ConfigParser'
...s very buggy, it crashes at first execute call.
– if __name__ is None
Dec 30 '12 at 14:46
15
@Jan...
Select distinct values from a table field
...odel is 'Shop'
class Shop(models.Model):
street = models.CharField(max_length=150)
city = models.CharField(max_length=150)
# some of your models may have explicit ordering
class Meta:
ordering = ('city')
Since you may have the Meta class ordering attribute set, you can us...
See changes to a specific file using git
...
Use a command like:
git diff file_2.rb
See the git diff documentation for full information on the kinds of things you can get differences for.
Normally, git diff by itself shows all the changes in the whole repository (not just the current directory).
...
Remove duplicate entries using a Bash script [duplicate]
...
Perl one-liner similar to @kev's awk solution:
perl -ne 'print if ! $a{$_}++' input
This variation removes trailing whitespace before comparing:
perl -lne 's/\s*$//; print if ! $a{$_}++' input
This variation edits the file in-place:
perl -i -ne 'print if ! $a{$_}++' input
This variation e...