大约有 40,000 项符合查询结果（耗时：0.0591秒） [XML]
Rails where condition using NOT NIL
..., so you really should just use the joins predicate:
Foo.joins(:bar)
Select * from Foo Inner Join Bars ...
But, for the record, if you want a "NOT NULL" condition simply use the not predicate:
Foo.includes(:bar).where.not(bars: {id: nil})
Select * from Foo Left Outer Join Bars on .. WHERE ...
Bootstrap 3 jquery event for active tab change
...
Okok... added :empty selector.
– Gerben Rampaart
Dec 20 '13 at 15:09
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R cannot be resolved - Android error
...
Myself also. And when I selected the SDK manager, lo and behold, the build tools shows up auto-checked for installing, with a note that it wasn't installed! What gives???
– David at HotspotOffice
Jun 3 '13 at 2...
Why does dividing two int not yield the right value when assigned to double?
...oo(int);
void foo(double);
void (*p)(double) = &foo; // automatically selects `foo(fouble)`
This is one context where the left-hand side of an assignment/initialization affects the behavior of the right-hand side. (Also, reference-to-array initialization prevents array type decay, which is an...
Best introduction to C++ template metaprogramming? [closed]
...ile-Time Assertions", 2.4 "Mapping Integral Constants to Types", 2.6 "Type Selection", 2.7 "Detecting Convertibility and Inheritance at Compile Time", 2.9 "NullType and EmptyType" and 2.10 "Type Traits".
The best intermediate/advanced resource I've found is C++ Template Metaprogramming by David Abr...
How To Launch Git Bash from DOS Command Line?
...rs maybe have C:\Program Files\Git
find the PATH environment variable and select it. Click Edit. (If the PATH environment variable does not exist, click New).
In the Edit window, add a new value %GIT_HOME% and %GIT_HOME%\bin. Click OK. Close all remaining windows by clicking OK.
[Make sure you clo...
How can I get the latest JRE / JDK as a zip file rather than EXE or MSI installer? [closed]
...mp; drop jdk1.6.0_31.msi or jre1.6.0_31.msi on the icon of UniExtract.exe.
Select "Extract Method: MSI Administrative Installer". Wait for the process to finish.
Enter the new created folder.
If you've drag-and-dropped jre1.6.0_31.msi you should have a jre1.6.0_31 folder
Follow all levels inside an...
Permission is only granted to system app
...; Editor -> Inspections then expand Android > Lint > Correctness. Select "Using system app permission", change severity or uncheck the checkbox.
– Ezekiel Baniaga
Apr 9 '18 at 3:48
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WinDbg基础资料（日本語） - IT优秀资料 - 清泛网 - 专注C/C++及内核技术
...ックする、
「Atach to Process」画面の「Atach to」の「Select..」ボタンをクリックする。
「Select Code Type」画面で、「Debug these code type:」のRadio BoxをCheck ONにして、
「Managed」と「Native」をCheck ONにして、OKボタンで画...
Algorithm to randomly generate an aesthetically-pleasing color palette [closed]
...h new color is chosen to maximize its euclidian distance to the previously selected ones.
Here you can find a a good implementation in javascript:
http://afriggeri.github.com/RYB/
UPDATE 2:
The Sciences Po Medialb have just released a tool called "I want Hue" that generate color palettes for da...