大约有 47,000 项符合查询结果(耗时:0.0513秒) [XML]
MySQL CONCAT returns NULL if any field contain NULL
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convert the NULL values with empty string by wrapping it in COALESCE
SELECT CONCAT(COALESCE(`affiliate_name`,''),'-',COALESCE(`model`,''),'-',COALESCE(`ip`,''),'-',COALESCE(`os_type`,''),'-',COALESCE(`os_version`,'')) AS device_name
FROM devices
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How to join two JavaScript Objects, without using JQUERY [duplicate]
... merge them and crete a single json object.
The resultant json should have all the values from obj2 and the values from obj1 which is not present in obj2.
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Crontab Day of the Week syntax
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@Nikita check for typos or extra spaces. I have both a "Mon-Fri" and a "Thu" in my crontab on Ubuntu 14.04.3 and both work just fine. I suspect if there's a space between any of the characters, you'd end up with an error.
– Dale A...
how to break the _.each function in underscore.js
...t provide to escape the loop (other than throwing an exception).
However, all hope is not lost! You can use the Array.every method. :)
From that link:
every executes the provided callback function once for each element present in the array until it finds one where callback returns a false valu...
How to make an immutable object in Python?
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Can you use namedtuple internally inside the class instead of instantiating the object externally? I'm very new to python but the advantage to your other answer is that I can have a class hide the details and also have the power of things like optional p...
What is a reasonable length limit on person “Name” fields?
..., and take their names with them.
For example, Spanish people with those extra surnames can move to and live in an English-speaking country, and can reasonably expect their full name to be used. Russians have patronymics in addition to their surnames, some African names can be considerably longer ...
How to URL encode a string in Ruby
How do I URI::encode a string like:
8 Answers
8
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What are the differences between Abstract Factory and Factory design patterns?
...ase.
interface IMessageQueueFactory
{
IMessageQueue CreateOutboundQueue(string name);
IMessageQueue CreateReplyQueue(string name);
}
public class AzureServiceBusQueueFactory : IMessageQueueFactory
{
IMessageQueue CreateOutboundQueue(string name)
{
//init queue
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How can I combine flexbox and vertical scroll in a full-height app?
... to zero rather than min-content) and they'll suddenly get squished by the extra-tall <article> element.)
You can simplify the <article> flex too - just set flex: 1; and you'll be good to go. Try to stick with the common values in https://drafts.csswg.org/css-flexbox/#flex-common unless...
Counting the occurrences / frequency of array elements
...e values as object keys to count them means you're casting those values to strings and then counting that value. [5, "5"] will simply say you've got "5" two times. Or counting instances some different objects is just gonna tell you there's a lot of [object Object]. Etc. etc.
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