大约有 26,000 项符合查询结果（耗时：0.0508秒） [XML]
How to do SELECT COUNT(*) GROUP BY and ORDER BY in Django?
...
According to the documentation, you should use:
from django.db.models import Count
Transaction.objects.all().values('actor').annotate(total=Count('actor')).order_by('total')
values() : specifies which columns are going to be used to "group by"
D...
How can I combine two commits into one commit? [duplicate]
...ebase.
If you're currently on your "commit 1", and the commit you want to merge, "commit 2", is the previous commit, you can run git rebase -i HEAD~2, which will spawn an editor listing all the commits the rebase will traverse. You should see two lines starting with "pick". To proceed with squashin...
bootstrap button shows blue outline when clicked
...when not navigating with a mouse. If you remove the outline you must add some other visual feedback, or you will have crippled your site.
– Josef Engelfrost
Aug 8 '17 at 14:29
...
promise already under evaluation: recursive default argument reference or earlier problems?
...
Formal arguments of the form x=x cause this. Eliminating the two instances where they occur we get:
f <- function(x, T) {
10 * sin(0.3 * x) * sin(1.3 * x^2) + 0.001 * x^3 + 0.2 * x + 80
}
g <- function(x, T, f. = f) { ## 1...
Get element from within an iFrame
How do you get a <div> from within an <iframe> ?
7 Answers
7
...
How to check if current thread is not main thread
...
add a comment
|
125
...
Can I add jars to maven 2 build classpath without installing them?
Maven2 is driving me crazy during the experimentation / quick and dirty mock-up phase of development.
24 Answers
...
setuptools: package data folder location
...he files will live on a user's
system, which may be Windows, Mac, Linux, some mobile platform, or inside an Egg. You can
always find the directory data relative to your Python package root, no matter where or how it is installed.
For example, if I have a project layout like so:
project/
foo/
...
Why invoke Thread.currentThread.interrupt() in a catch InterruptException block?
Why invoke the method Thread.currentThread.interrupt() in the catch block?
5 Answers
...
How to update column with null value
...
No special syntax:
CREATE TABLE your_table (some_id int, your_column varchar(100));
INSERT INTO your_table VALUES (1, 'Hello');
UPDATE your_table
SET your_column = NULL
WHERE some_id = 1;
SELECT * FROM your_table WHERE your_column IS NULL;
+---------+-------------...