大约有 3,551 项符合查询结果（耗时：0.0397秒） [XML]
Servlet for serving static content
...y project. The only method you need is coalesce (which is identical to the SQL function COALESCE). This is the code:
public static <T> T coalesce(T...ts) {
for(T t: ts)
if(t != null)
return t;
return null;
}
...
postgresql return 0 if returned value is null
...re NULL values in the query.
For all versions I've tested, postgres and mysql will ignore all NULL values when averaging, and it will return NULL if there is nothing to average over. This generally makes sense, as NULL is to be considered "unknown". If you want to override this you can use coalesc...
Preventing Laravel adding multiple records to a pivot table
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@alexandre Butynsky method works very well but use two sql queries.
One to check if cart contains the item and one to save.
To use only one query use this:
try {
$cart->items()->save($newItem);
}
catch(\Exception $e) {}
...
WebSockets vs. Server-Sent events/EventSource
..., or other automated data push mechanisms (e.g. updating a client-side Web SQL Database or IndexedDB object store). If you'll need to send data to a server, XMLHttpRequest is always a friend.
SSEs are sent over traditional HTTP. That means they do not require a special protocol or server implem...
How to select different app.config for several build configurations
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$(ProjectDir)App.Config.Settings.xls
MachineName ConfigFilePath SQLServer
default App.config DEVSQL005
Test App.config TESTSQL005
UAT App.config UATSQL005
Production App.config PRODSQL005
YourLocalMachine ...
Multiple queries executed in java in single statement
... as it currently provides an exception even though it is possible in the MySQL query browser.
6 Answers
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In C#, how do I calculate someone's age based on a DateTime type birthday?
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Actually this is great for usage on MS-SQL with datetime-fields (total days since 01-011900)
– Patrik
Jul 3 '15 at 12:01
5
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Difference between HBase and Hadoop/HDFS
This is kind of naive question but I am new to NoSQL paradigm and don't know much about it. So if somebody can help me clearly understand difference between the HBase and Hadoop or if give some pointers which might help me understand the difference.
...
Why does this assert throw a format exception when comparing structures?
...en't expecting foo nor was the actual value bar!
Basically this is like a SQL injection attack, but in the rather less scary context of string.Format.
As a workaround, you can use string.Formatas StriplingWarrior suggests. That avoids the second level of formatting being performed on the result of...
Storing custom objects in an NSMutableArray in NSUserDefaults
...erDefaults shouldn't be used for storage of large arrays (Core Data or raw SQLite should be used for that instead), but it's perfectly fine to stash small arrays of encoded objects there. In any case, the question was asking how to do this, which is what the above code provides. As far as the votes,...