大约有 47,000 项符合查询结果（耗时：0.0841秒） [XML]
Is MVC a Design Pattern or Architectural pattern
...P ( view ), JavaBeans ( Model ), Servlet ( controller ). Same concept with all the famous php framework ( symphony, zend, cake etc. ). But nowaday frontend frameworks looks like back end application and modern javascript frameworks use mvc ( html your view, controller your script, and model your j...
Status bar won't disappear
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How to do this globally?
– jjxtra
Aug 25 '13 at 19:44
16
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Go to back directory browsing after opening file in vim
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Nice thing summarizing all the other correct answers, I wish more people do that.
– LightMan
Jul 19 '18 at 8:57
1
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How to set up a git project to use an external repo submodule?
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You have a project -- call it MyWebApp that already has a github repo
You want to use the jquery repository in your project
You want to pull the jquery repo into your project as a submodule.
Submodules are really, really easy to reference and use...
Using Laravel Homestead: 'no input file specified'
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Instead of reinstalling try
vagrant up --provision
or
homestead up --provision
share
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fo...
Set up a scheduled job?
...Django, and I'm curious if there is a way to schedule a job to run periodically.
24 Answers
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Counting null and non-null values in a single query
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If I understood correctly you want to count all NULL and all NOT NULL in a column...
If that is correct:
SELECT count(*) FROM us WHERE a IS NULL
UNION ALL
SELECT count(*) FROM us WHERE a IS NOT NULL
Edited to have the full query, after reading the comments :]
S...
postgresql return 0 if returned value is null
...ns the first of its arguments that is not null.
Null is returned only if all arguments are null. It is often
used to substitute a default value for null values when data is
retrieved for display.
Edit
Here's an example of COALESCE with your query:
SELECT AVG( price )
FROM(
SELECT *, cum...
How does a Java HashMap handle different objects with the same hash code?
...ng bucket, and then it will compare the key that you gave with the keys of all pairs in the bucket, by comparing them with equals().
Now you can see how this is very efficient for looking up key-value pairs in a map: by the hash code of the key the hashmap immediately knows in which bucket to look,...
The remote end hung up unexpectedly while git cloning
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Quick solution:
With this kind of error, I usually start by raising the postBuffer size by:
git config --global http.postBuffer 524288000
(some comments below report having to double the value):
git config --global http.postBuffer 1048576000
More information:
From...