This post provides a simple IValueConverter implementation that makes use of the framework type converters in order to convert between a large range of source / target types. This converter can be used both within bindings and in code-behind to give more concise property setters. 

SQL Server tutorial for beginners
150 videos
In this tutorial, we will start from the very basics and cover topics like joins, views, triggers, system functions, stored procedures, user defined scalar and table valued functions etc. These video tutorials will be useful for frehsers, experienced .NET and SQL Database developers.  

Team Explorer support for TLSv1.2

• We have updated the Git and the Git Credential Manager components that ship in Visual Studio.
• The optional Git for Windows component has also been updated.
• This update allows Git to connect to services that have deprecated support for TLSv1 and TLSv1.1 in favor of TLSv1.2.

Issues Fixed in this Release

These are the customer-reported issues addressed in this release:

• Projects targeting .NET Core 2.1 or newer are not supported by Visual Studio 2017 version 15.5.
• Fixed issue where installation of the SDK for .NET Core 2.1 or newer would cause the option to create ASP.NET Core 2.0 Web applications to disappear. 

        [HttpPost]
        public ActionResult Edit(User user, string[] tags)
        {
            User Currentuser = db.Users.Find(user.Id);

            Currentuser.FirstName = user.FirstName;
            Currentuser.LastName = user.LastName;
            if (ModelState.IsValid)
            {
                List<Role> roles = new List<Role>();
                if (Currentuser.Roles != null && Currentuser.Roles.Any())
                    Currentuser.Roles.Clear();
                foreach (var item in tags)
                {
                    Role role = db.Roles.Find(long.Parse(item));
                    roles.Add(role);
                }
                Currentuser.Roles = roles;

                db.Entry(Currentuser).State = EntityState.Modified;
                db.SaveChanges();
                return RedirectToAction("Index");
            }
            return View(Currentuser);
        }

CREATE TABLE ftsXML(
id INT IDENTITY PRIMARY KEY,
doc XML NULL
CONSTRAINT UQ_FTS_Id UNIQUE(id)
)
GO
INSERT ftsXML VALUES('
<book>
<title>Sample book title 1</title>
<author>Vahid</author>
<chapter ID="1">
<title>Chapter 1</title>
<content>
"The quick brown fox jumps over the lazy dog" is an English-language 
pangram—a phrase that contains all of the letters of the English alphabet. 
It has been used to test typewriters and computer keyboards, and in other 
applications involving all of the letters in the English alphabet. Owing to its 
brevity and coherence, it has become widely known.
</content>
</chapter>
<chapter ID="2">
<title>Chapter 2</title>
<content>
In publishing and graphic design, lorem ipsum is a placeholder text commonly used 
to demonstrate the graphic elements of a document or visual presentation. 
By replacing the distraction of meaningful content with filler text of scrambled 
Latin it allows viewers to focus on graphical elements such as font, typography, 
and layout.
</content>
</chapter>
</book>
')

INSERT ftsXML VALUES('
<book>
<title>Sample book title 2</title>
<author>Farid</author>
<chapter ID="1">
<title>Chapter 1</title>
<content>
The original passage began: Neque porro quisquam est qui dolorem ipsum quia dolor sit 
amet consectetur adipisci velit 
</content>
</chapter>
<chapter ID="2">
<title>Chapter 2</title>
<content>
Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor 
incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis 
nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. 
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore 
eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, 
sunt in culpa qui officia deserunt mollit anim id est laborum.
</content>
</chapter>
</book>
')
GO

 CREATE FULLTEXT CATALOG FT_CATALOG
GO
CREATE FULLTEXT INDEX ON ftsXML([doc])
KEY INDEX UQ_FTS_Id ON ([FT_CATALOG], FILEGROUP [PRIMARY])
GO

 SQL Server encountered error 0x80070422 while communicating with full-text filter daemon host (FDHost) process.

 sp_fulltext_service 'restart_all_fdhosts'
go

 -- استفاده از ایکس کوئری برای جستجو در نتایج حاصل
SELECT T.doc.value('(/book/title)[1]', 'varchar(100)') AS title
FROM
-- استفاده از اف تی اس برای جستجو
(SELECT * FROM ftsXML
WHERE CONTAINS(doc, '"Quick Brown Fox "')) AS T

 SELECT T.doc.value('(/book/title)[1]', 'varchar(100)') AS title
FROM
(SELECT * FROM ftsXML
WHERE CONTAINS(doc, 'FORMSOF (INFLECTIONAL ,"Quick Brown Fox jumped")')) AS T

 SELECT T.doc.value('(/book/title)[1]', 'varchar(100)') AS title
FROM
(SELECT * FROM ftsXML
WHERE CONTAINS(doc, 'quick NEAR fox')) AS T

 SELECT doc.value('(/book/title)[1]', 'varchar(100)') AS title
FROM ftsXML
WHERE doc.exist('/book/chapter/content[contains(., "Quick Brown Fox")]') = 1

declare @cntr_value bigint

Select @cntr_value=cntr_value
from sys.dm_os_performance_counters
where instance_name='AdventureWorks' and
counter_name='Write Transactions/sec'

/* ایجاد یک تاخیر مثلاً یک ثانیه */
waitfor delay '00:00:01'

Select cntr_value -@cntr_value
from sys.dm_os_performance_counters
where instance_name='AdventureWorks' and
counter_name='Write Transactions/sec'

EXEC sys.sp_MSforeachtable 'sp_spaceused ''?''';

 USE [AdventureWorksDW2008R2]
GO

CREATE TABLE #TableSpaceUsed(
[name] [nvarchar](120) NULL,
[rows] [nvarchar](120) NULL,
[reserved] [nvarchar](120) NULL,
[data] [nvarchar](120) NULL,
[index_size] [nvarchar](120) NULL,
[unused] [nvarchar](120) NULL
) ON [PRIMARY]

Insert Into #TableSpaceUsed
EXEC sys.sp_MSforeachtable 'sp_spaceused ''?''';

Select * from #TableSpaceUsed
Order by CAST([rows] as int) desc

Drop table #TableSpaceUsed

Database Engineering Complete Course | DBMS Complete Course
In this program, you’ll learn:
Core techniques and methods to structure and manage databases.
Advanced techniques to write database driven applications and advanced data modeling concepts.
MySQL database management system (DBMS) and data creation, querying and manipulation.
How to code and use Python Syntax
How to prepare for technical interviews for database engineer roles.
 

We’re excited to announce general availability of F# 4.7 in conjunction with the .NET Core 3.0 release! In this post, I’ll show you how to get started, explain everything in F# 4.7 and give you a sneak peek at what we’re doing for the next version of F#. 

 var date = new DateOnly(2020, 04, 20);

 var currentDate = DateOnly.FromDateTime(DateTime.Now);

if (DateOnly.TryParse("28/09/1984", new CultureInfo("en-US"), DateTimeStyles.None, out var result))
{
   Console.WriteLine(result);
}

DateOnly d1 = DateOnly.ParseExact("31 Dec 1980", "dd MMM yyyy", CultureInfo.InvariantCulture);  // Custom format
Console.WriteLine(d1.ToString("o", CultureInfo.InvariantCulture)); // "1980-12-31"  (ISO 8601 format)

var persianCalendar = new PersianCalendar();
DateOnly d2 = new DateOnly(1400, 9, 6, persianCalendar);
Console.WriteLine(d2.ToString("d MMMM yyyy", CultureInfo.InvariantCulture));

var newDate = date.AddDays(1).AddMonths(1).AddYears(1)

public TimeOnly(int hour, int minute)
public TimeOnly(int hour, int minute, int second)
public TimeOnly(int hour, int minute, int second, int millisecond)

var startTime = new TimeOnly(10, 30);

var endTime = new TimeOnly(13, 00, 00);

var diff = endTime - startTime;

Console.WriteLine($"Hours: {diff.TotalHours}");

TimeSpan ts = endTime.ToTimeSpan();

var currentTime = TimeOnly.FromDateTime(DateTime.Now);

DateTime dt = date.ToDateTime(new TimeOnly(0, 0));
Console.WriteLine(dt);

 var isBetween = currentTime.IsBetween(startTime, endTime);
Console.WriteLine($"Current time {(isBetween ? "is" : "is not")} between start and end");

var startTime = new TimeOnly(08, 00);
var endTime = new TimeOnly(09, 00);
 
Console.WriteLine($"{startTime < endTime}");

TimeOnly time = TimeOnly.ParseExact("5:00 pm", "h:mm tt", CultureInfo.InvariantCulture);  // Custom format
Console.WriteLine(time.ToString("T", CultureInfo.InvariantCulture)); // "17:00:00"  (long time format)

public record DataTypeTest(DateOnly Date, TimeOnly Time);

var date = DateOnly.FromDateTime(DateTime.Now);
var time = TimeOnly.FromDateTime(DateTime.Now);
var test = new DataTypeTest(date, time);
var json = JsonSerializer.Serialize(test);

Serialization and deserialization of 'System.DateOnly' instances are not supported.

    public class DateOnlyConverter : JsonConverter<DateOnly>
    {
        private readonly string _serializationFormat;

        public DateOnlyConverter() : this(null)
        { }

        public DateOnlyConverter(string? serializationFormat)
        {
            _serializationFormat = serializationFormat ?? "yyyy-MM-dd";
        }

        public override DateOnly Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            var value = reader.GetString();
            return DateOnly.ParseExact(value!, _serializationFormat, CultureInfo.InvariantCulture);
        }

        public override void Write(Utf8JsonWriter writer, DateOnly value, JsonSerializerOptions options)
            => writer.WriteStringValue(value.ToString(_serializationFormat));
    }

    public class TimeOnlyConverter : JsonConverter<TimeOnly>
    {
        private readonly string _serializationFormat;

        public TimeOnlyConverter() : this(null)
        {
        }

        public TimeOnlyConverter(string? serializationFormat)
        {
            _serializationFormat = serializationFormat ?? "HH:mm:ss.fff";
        }

        public override TimeOnly Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            var value = reader.GetString();
            return TimeOnly.ParseExact(value!, _serializationFormat, CultureInfo.InvariantCulture);
        }

        public override void Write(Utf8JsonWriter writer, TimeOnly value, JsonSerializerOptions options)
            => writer.WriteStringValue(value.ToString(_serializationFormat));
    }

var jsonOptions = new JsonSerializerOptions(JsonSerializerDefaults.Web);
jsonOptions.Converters.Add(new DateOnlyConverter());
jsonOptions.Converters.Add(new TimeOnlyConverter());
var json = JsonSerializer.Serialize(test, jsonOptions);