大约有 10,900 项符合查询结果（耗时：0.0390秒） [XML]
How to get the original value of an attribute in Rails
...attribute will give you the previous value.
For rails 5.1+
Copied from Lucas Andrade's answer below: https://stackoverflow.com/a/50973808/9359123
Appending _was is deprecated in rails 5.1, now you should append _before_last_save
Something like:
before_save object
do_something_with object.n...
Can a dictionary be passed to django models on create?
...
If title and body are fields in your model, then you can deliver the keyword arguments in your dictionary using the ** operator.
Assuming your model is called MyModel:
# create instance of model
m = MyModel(**data_dict)
# don't forget to save to database!
m.save()
As for yo...
Warning the user/local/mysql/data directory is not owned by the mysql user
I can't start the mysql service in Snow Leopard, and in the panel prefs appears the message,
2 Answers
...
How I can delete in VIM all text from current line to end of file?
...ving the file.
head hugefile > firstlines
(If you are on Windows you can use the Win32 port of head)
share
|
improve this answer
|
follow
|
...
What does an underscore in front of an import statement mean?
...'s for importing a package solely for its side-effects.
From the Go Specification:
To import a package solely for its side-effects (initialization), use the blank identifier as explicit package name:
import _ "lib/math"
In sqlite3
In the case of go-sqlite3, the underscore import is used for the si...
How can I add a boolean value to a NSDictionary?
...would use NSNumber . But YES and NO aren't objects, I guess. A.f.a.i.k. I can only add objects to an NSDictionary , right?
...
What is the “reactor” in Maven?
...s terminology usage. I've read that a multi-module is a reactor, that you can manipulate the maven reactor and that the reactor is a plugin. What exactly is the reactor?
...
What events does an fire when it's value is changed?
...
Note that .bind() is now deprecated in favor of .on()
– Michael Hays
May 10 '17 at 18:31
...
How did this person code “Hello World” with Microsoft Paint?
I have just seen this within the past few days and cannot figure out how it works. The video I talk about is here :
3 Ans...
How do I combine two data frames?
...
I believe you can use the append method
bigdata = data1.append(data2, ignore_index=True)
to keep their indexes just dont use the ignore_index keyword ...
share
...