Input Validation for me is about validating the user input. Some people call "Name must not be empty" a business rule, I think about it as input validation. Business Rules validation is more complex, because a business rule for me is not "Name must not be empty", it is a definition of a state in the system that requires an action. Here is a definition of a business rule:
An order should be payed within 30 days, this duration can be extended, to a maximum of three times.
Stairway to XML
XML has been part of the SQL Standard since 2003, and is essential for
any DBA because so many of the dynamic management views return XML data.
Now that the industry is more used to data defined by document markup,
it is becoming more important than ever for Database Developers and DBAs
to understand the technology and to know where it makes sense to use
XML. In this book, originally a series of articles on
SQLServerCentral.com, Robert Sheldon flexes his talent to make the
complicated seem simple.
ASP.NET Core News is the only weekly newsletter dedicated to ASP.NET Core. Whether you build Razor Pages, MVC applications, Web APIs, SignalR awesomeness, or anything else available on the ASP.NET Core platform, we've got you covered. Every Friday you will receive a weekly digest of the most interesting posts and articles from the last seven days.
var nums = Enumerable.Range( 0, 1000000 ).ToArray();
long total = 0;
// Use type parameter to make subtotal a long, not an int
Parallel.For< long >( 0, nums.Length, () => 0,
( j, loop, subtotal ) =>
{
subtotal += nums[j];
return subtotal;
},
x => Interlocked.Add( ref total, x ) );
Console.WriteLine( "The total is {0:N0}", total ); var nums = Enumerable.Range( 0, 1000000 ).ToArray();
long total = 0;
Parallel.ForEach< int, long >( nums, // source collection
() => 0, // method to initialize the local variable
( j, loop, subtotal ) => // method invoked by the loop on each iteration
{
subtotal += j; //modify local variable
return subtotal; // value to be passed to next iteration
},
// Method to be executed when each partition has completed.
// finalResult is the final value of subtotal for a particular partition.
finalResult => Interlocked.Add( ref total, finalResult ) );
Console.WriteLine( "The total from Parallel.ForEach is {0:N0}", total ); Console.WriteLine("IsInfinity(3.0 / 0) == {0}.", double.IsInfinity(3.0 / 0) ? "true" : "false"); با استفاده از نوع dynamic می توان عملیات چک کردن نوع در زمان کامپایل را پشت سر گذاشت و در عوض این عملیات را به زمان اجرا، موکول داد.
نکته: نوع dynamic همانند نوع object در بسیاری از شرایط، یکسان رفتار می‌کند. اگرچه عملیات‌هایی که شامل عبارت‌هایی از نوع dynamic هستند، یا نوع آن توسط کامپایلر بررسی می‌شوند و یا پذیرفته نمی‌شوند. کامپایلر اطلاعات مربوط به یک پردازش (روند) را یکجا بسته بندی می‌کند و این اطلاعات را بعداً در زمان اجرا ارزیابی می‌کند. به عنوان بخشی از این پردازش، متغیرهایی از نوع dynamic به متغیرهایی از نوع object کامپایل می‌شوند. بنابراین نوع dynamic فقط در زمان کامپایل وجود دارند (نه در زمان اجرا).
var i = 20;
dynamic dynamicVariable = i;
Console.WriteLine( dynamicVariable );
var stringVariable = "Example string.";
dynamicVariable = stringVariable;
Console.WriteLine( dynamicVariable );
var dateTimeVariable = DateTime.Today;
dynamicVariable = dateTimeVariable;
Console.WriteLine( dynamicVariable );
// The expression returns true unless dynamicVariable has the value null.
if ( dynamicVariable is dynamic )
Console.WriteLine( "dynamicVariable variable is dynamic" );
// dynamic and the as operator.
dynamicVariable = i as dynamic;
// throw RuntimeBinderException if the associated object doesn't have the specified method.
// The code is still compiling successfully.
Console.WriteLine( dynamicVariable.ToNow1 ); همانطور که در مثال بالا مشاهده می‌کنید، شما می‌توانید متغیرهایی از نوع‌های مختلف را به یک شی از نوع dynamic اختصاص دهید. همچنین می‌توانید برای بررسی یک متغیر که از نوع dynamic است یا خیر، از عملگر is استفاده کنید. اگر یک خصوصیت را که وجود ندارد، درخواست کنید (خط آخر مثال بالا)، خطای RuntimeBinderException پرتاب می‌شود.
dynamic sampleObject = new ExpandoObject();
sampleObject.FirstName = "Vahid";
sampleObject.LastName = "Mohammad Taheri";
sampleObject.Age = "28";
sampleObject.TestRemoveProperty = DateTime.Now;
sampleObject.AsString = new Action( () => Console.WriteLine( "{0} {1} is {2} years old.",
sampleObject.FirstName,
sampleObject.LastName,
sampleObject.Age ) );
sampleObject.AsString(); ( (IDictionary< String, Object >)sampleObject ).Remove( "TestRemoveProperty" );
This Bash script automates the optimization of your Linux server.
This teacher is Bob Ziroll, Head of Education at Scrimba
What is concurrent programing? Simply described, it’s when you are doing more than one thing at the same time. Not to be confused with parallelism, concurrency is when multiple sequences of operations are run in overlapping periods of time. In the realm of programming, concurrency is a pretty complex subject. Dealing with constructs such as threads and locks and avoiding issues like race conditions and deadlocks can be quite cumbersome, making concurrent programs difficult to write. Through concurrency, programs can be designed as independent processes working together in a specific composition. Such a structure may or may not be made parallel; however, achieving such a structure in your program offers numerous advantages.
To update a document in MongoDB, I used to fetch it, update the values, and save back the entry. I would question the need for an update method. Looking back, it's evident that performance optimizations were hardly a concern when working on a personal project.
