大约有 47,000 项符合查询结果（耗时：0.0279秒） [XML]
Which is fastest? SELECT SQL_CALC_FOUND_ROWS FROM `table`, or SELECT COUNT(*)
...irm this - I just updated a query with 4 joins on a 168,000 row database. Selecting just the first 100 rows with a SQL_CALC_FOUND_ROWS took over 20 seconds; using a separate COUNT(*) query took under 5 seconds (for both count + results queries).
– Sam Dufel
Ju...
How do I convert between big-endian and little-endian values in C++?
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@MihaiTodor: This use of unions for typecasting through an array of chars is explicitly allowed by the standard. See eg. this question.
– Alexandre C.
May 4 '14 at 12:36
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How to get an object's property's value by property name?
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Sure
write-host ($obj | Select -ExpandProperty "SomeProp")
Or for that matter:
$obj."SomeProp"
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What is the Swift equivalent of isEqualToString in Objective-C?
... operator because String in swift is of type struct not class. If you type cast your text/string as NSString you can compare using === operator.
– sanjana
Jun 14 '15 at 1:05
3
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TSQL Pivot without aggregate function
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yes, but why !!??
Select CustomerID,
Min(Case DBColumnName When 'FirstName' Then Data End) FirstName,
Min(Case DBColumnName When 'MiddleName' Then Data End) MiddleName,
Min(Case DBColumnName When 'LastName' Then Data End) LastNa...
How can I force division to be floating point? Division keeps rounding down to 0?
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You can cast to float by doing c = a / float(b). If the numerator or denominator is a float, then the result will be also.
A caveat: as commenters have pointed out, this won't work if b might be something other than an integer or ...
How to create an installer for a .net Windows Service using Visual Studio
...out dragging stuff from the toolbox.
Then right click on the gray area and select add installer. This will add an installer project file to your project.
Then you will have 2 components on the design view of the ProjectInstaller.cs (serviceProcessInstaller1 and serviceInstaller1). You should then se...
mysql :: insert into table, data from another table?
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INSERT INTO action_2_members (campaign_id, mobile, vote, vote_date)
SELECT campaign_id, from_number, received_msg, date_received
FROM `received_txts`
WHERE `campaign_id` = '8'
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What are Aggregates and PODs and how/why are they special?
...ns (10.3) and no virtual base classes (10.1), and
— the constructor selected to copy/move each direct base class subobject is trivial, and
— for each non-static data member of X that is of class type (or array thereof), the constructor
selected to copy/move that member is trivial;
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What good technology podcasts are out there?
Yes, Podcasts, those nice little Audiobooks I can listen to on the way to work. With the current amount of Podcasts, it's like searching a needle in a haystack, except that the haystack happens to be the Internet and is filled with too many of these "Hot new Gadgets" stuff :(
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