大约有 1,900 项符合查询结果（耗时：0.0114秒） [XML]
Limiting the number of records from mysqldump?
...ault to and advise "id" for PK-columns, since it is redundant to say users.user_id instead of just users.id.
– Andreas Bergström
Nov 23 '17 at 8:50
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how to permit an array with strong parameters
...y
params.require(:question).permit(:question_details, :question_content, :user_id, :accepted_answer_id, :province_id, :city, :category_ids => [])
Works perfectly now!
(IMPORTANT: As @Lenart notes in the comments, the array declarations must be at the end of the attributes list, otherwise you'...
How to make pipes work with Runtime.exec()?
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I ran into a similar problem in Linux, except it was "ps -ef | grep someprocess".
At least with "ls" you have a language-independent (albeit slower) Java replacement. Eg.:
File f = new File("C:\\");
String[] files = f.listFiles(new File("/home/tihamer"));
for (String file : fi...
Best practice for instantiating a new Android Fragment
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This approach is also documented in the android developer reference: https://developer.android.com/reference/android/app/Fragment.html
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delete_all vs destroy_all?
...l
You can do :
u = User.find_by_name('JohnBoy')
UsageIndex.destroy_all "user_id = #{u.id}"
The result is one query to destroy all the associated records
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Get started with Latex on Linux [closed]
...D$. The function $f$ is said to be \emph{continuous} on
$D$ if, for all $\epsilon > 0$ and for all $x \in D$,
there exists some $\delta > 0$ (which may depend on $x$)
such that if $y \in D$ satisfies
\[ |y - x| < \delta \]
then
\[ |f(y) - f(x)| < \epsilon. \]
One may readily verify that...
What is the meaning of the CascadeType.ALL for a @ManyToOne JPA association
...dresses {
@ManyToOne(cascade = CascadeType.REFRESH) @JoinColumn(name = "user_id")
protected User addressOwner;
}
This way you dont need to worry about using fetch in annotations. But remember when deleting the User you will also delete connected address to user object.
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Can linux cat command be used for writing text to file?
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The > characters represent the default value of $PS2; they show up automatically, and are not meant to be typed. If you have a different value for $PS2, that will show up instead.
– gbrener
Jun 5 '18 at 15:13
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Command line to remove an environment variable from the OS level configuration
...following.
Save the PowerShell script to a file (we'll call it updateenv.ps1).
Do this from the command line: reg delete "HKCU\Environment" /v FOO /f
Run updateenv.ps1.
Close and reopen your command prompt, and you'll see that the environment variable is no longer defined.
Note, you'll probably ...
Should I be concerned about excess, non-running, Docker containers?
...r. If the container is no longer running it can still be seen with docker ps -a .
5 Answers
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