大约有 950 项符合查询结果（耗时：0.0103秒） [XML]
Splitting string into multiple rows in Oracle
... select 108 Name, 'test' Project, 'Err1, Err2, Err3' Error from dual
union all
select 109, 'test2', 'Err1' from dual
)
select distinct
t.name, t.project,
trim(regexp_substr(t.error, '[^,]+', 1, levels.column_value)) as error
from
temp t,
table(cast(multiset(select level from dual...
In what areas might the use of F# be more appropriate than C#? [closed]
...a structures used to represent program code in F# are mostly discriminated unions (which are not supported in C# in any reasonable way) and this makes a huge difference for this kind of application (where you need to process tree structures, such as program code). Discriminated unions and pattern ma...
How do Python functions handle the types of the parameters that you pass in?
...tively.
Iterable - useful for generators.
Any - when it could be anything.
Union - when it could be anything within a specified set of types, as opposed to Any.
Optional - when it might be None. Shorthand for Union[T, None].
TypeVar - used with generics.
Callable - used primarily for functions, but ...
做了个购物清单App后，我才真正搞懂App Inventor 2的变量 - App应用开发 - ...
...的积木能做出真正好用的App"。
复盘感悟
变量是编程的地基。App Inventor 2把变量简化为5种积木块——初始化全局、初始化局部(do)、初始化局部(return)、取值、设置值——看起来简单，但每个都有其使用场景：
- 全局变...
Excel RTD(Excel Real-Time Data)实时刷新数据技术 - C/C++ - 清泛网 - 专注C/C++及内核技术
..."
第一个变量 ProgID 表示Real-Time Data 服务器（RTD Server）的编程标识符 (ProgID)。Server 变量指示运行RTD Server的计算机的名称；如果RTD Server在本地运行，则可以将此变量设置为空字符串或将其忽略。其他变量只表示发送到RTD Server的...
App Inventor 2 低功耗蓝牙(BLE) 硬件接入、数据通信及IO控制 · App Inventor 2 中文网
...使用厂商提供的App进行IO口控制，也可以使用App Inventor 2 编程实现控制IO口电平的高/低，对应LED的开/关。
3、App Inventor 2 开发自己的蓝牙App
主要用到 BlueToothLE 拓展，点此查看中文文档。BLE蓝牙的特点是无需配对，设备被扫描...
How to filter SQL results in a has-many-through relation
...RE NOT EXISTS (
SELECT *
FROM (
SELECT 30 AS club_id
UNION ALL
SELECT 50
) AS c
WHERE NOT EXISTS (
SELECT *
FROM student_club AS sc
WHERE sc.stud_id = s.stud_id
AND sc.club_id = c.club_id
)
);
As expected, those two pe...
技术人员如何创业《一》—— 产品及想法 - 资讯 - 清泛网 - 专注C/C++及内核技术
...源优势（哈佛）。其实他这个php网站我想现在很多学过web编程的都可以制造出来，有几个能做成facebook呢？
在《中国合伙人》中也有个场景，成东青因为在外面开小班被大学辞退了。最后一堂课时改变了原有的讲课风格，原来...
Efficiency of purely functional programming
...n pure lambda calculus) is known, even with laziness.
The aforementioned union-find
Hash tables
Arrays
Some graph algorithms
...
However, we assume that in "imperative" languages access to memory is O(1) whereas in theory that can't be so asymptotically (i.e. for unbounded problem sizes) and acc...
再说WCF Data Contract KnownTypeAttribute - 更多技术 - 清泛网 - 专注IT技能提升
...一种标识方式是不用加代码的，在配置文件中通过声明型编程实现：
<system.runtime.serialization>
<dataContractSerializer>
<declaredTypes>
<add type="WcfServiceDemo.Address, MyAssembly, Version=2.0.0.0, Culture=neutral,PublicKeyToken=null, processorArchitect...