I&#39;m trying to learn how to use `UICollectionView`. The [documentation][1] is a little hard to understand and the tutorials that I found were either in Objective C or long complicated projects.

When I was learning how to use `UITableView`, *We ❤ Swift&#39;s* [How to make a simple tableview with iOS 8 and Swift][2] had a very basic setup and explanation to get me going. Is there anything like this for `UICollectionView`?

The answer below is my attempt to learn to do this.


  [1]: https://developer.apple.com/library/ios/documentation/UIKit/Reference/UICollectionView_class/
  [2]: https://www.weheartswift.com/how-to-make-a-simple-table-view-with-ios-8-and-swift/

How to make a simple collection view with Swift

For **java.util.Date** when I do  
  

    @JsonFormat(shape = JsonFormat.Shape.STRING, pattern = &quot;dd/MM/yyyy&quot;)  
      private Date dateOfBirth;

  

then in JSON request when I send   

    { {&quot;dateOfBirth&quot;:&quot;01/01/2000&quot;} }  

it works.

How should I do this for **Java 8&#39;s LocalDate** field??

I tried having   
  

    @JsonDeserialize(using = LocalDateDeserializer.class)  
    @JsonSerialize(using = LocalDateSerializer.class)  
    private LocalDate dateOfBirth;  

It didn&#39;t work.

Can someone please let me know what&#39;s the right way to do this..  

Below are dependencies
 

    &lt;dependency&gt;
        &lt;groupId&gt;org.jboss.resteasy&lt;/groupId&gt;
        &lt;artifactId&gt;jaxrs-api&lt;/artifactId&gt;
         &lt;version&gt;3.0.9.Final&lt;/version&gt;
    &lt;/dependency&gt;
    &lt;dependency&gt;
        &lt;groupId&gt;com.fasterxml.jackson.jaxrs&lt;/groupId&gt;
        &lt;artifactId&gt;jackson-jaxrs-json-provider&lt;/artifactId&gt;
        &lt;version&gt;2.4.2&lt;/version&gt;
    &lt;/dependency&gt;
    &lt;dependency&gt;
        &lt;groupId&gt;com.wordnik&lt;/groupId&gt;
        &lt;artifactId&gt;swagger-annotations&lt;/artifactId&gt;
        &lt;version&gt;1.3.10&lt;/version&gt;
    &lt;/dependency&gt;


Java 8 LocalDate Jackson format

Recently I used `dot Trace profiler` to find the bottlenecks in my application.

Suddenly, I have seen that in most of the places which are taking more time and more `CPU` usage to is `SNINativeMethodWrapper.SNIReadSyncOverAsync()` which is called by `Execute` reader method of `ADO.Net`, I don&#39;t know why it&#39;s taking more time. 

If I run the same query in `SQL server` it&#39;s running very fast. 

 1. Does anybody know why it&#39;s taking more time?
 2. What is the alternative for this `ADO.Net` method?

SNIReadSyncOverAsync Performance issue

Recently I used <code>dot Trace profiler</code> to find the bottlenecks in my application.
Suddenly, I have seen that in most of the places which are taking more time and more <code>CPU</code> usage to is <code>SNINativeMethodWrapper.SNIReadSyncOverAsync()</code> which is called by <code>Execute</code> reader method of <code>ADO.Net</code>, I don't know why it's taking more time.
If I run the same query in <code>SQL server</code> it's running very fast.
<ol>
<li>Does anybody know why it's taking more time?</li>
<li>What is the alternative for this <code>ADO.Net</code> method?</li>
</ol>

I was looking at the new features for Visual Studio 2015 and Shared Project came up a lot but I don&#39;t understand how it is different to using a Class Library or a Portable Class Library. Can anyone explain? 

**Edit:** Shared Project is a new feature in Visual Studio 2015 and is different to a Portable Class Library. I understand what a Portable Class Library is. What I&#39;m trying to understand is how a Shared Project differs to a Class Library. See link below. 

http://www.c-sharpcorner.com/UploadFile/7ca517/shared-project-an-impressive-features-of-visual-studio-201/

What is the difference between a Shared Project and a Class Library in Visual Studio 2015?

I am developing a TCP client to connect OpenSSL server with the certificate authentication. I have using .crt and .key files shared by server team. These certificates are generated by OpenSSL commands.

I am using [`SslStream`](https://msdn.microsoft.com/en-us/library/system.net.security.sslstream%28v=vs.85%29.aspx) object to authenticate the Tcp client by calling [`SslStream.AuthenticateAsClient`](https://msdn.microsoft.com/en-us/library/system.net.security.sslstream.beginauthenticateasclient%28v=vs.85%29.aspx) method by passing server `IP`, [`SslProtocols.Ssl3`](https://msdn.microsoft.com/en-us/library/system.security.authentication.sslprotocols%28v=vs.85%29.aspx) and `X509CertificateCollection`.

I am getting the following error:

&gt; Authentication failed because the remote party has closed the transport stream


Authentication failed because remote party has closed the transport stream

The default value for `int` is 0 , for `string` is &quot;&quot; and for `boolean` it is false. Could someone please clarify what the default value for `guid` is?  


What is the default value for Guid?

I am using EF6 for storing instances of the `report` class in my database. The database already contains data. Say I wanted to add a property to `report`, 

    public class report {
        // ... some previous properties
    
        // ... new property:
        public string newProperty{ get; set; }
    }

Now if I go to the package-manager console and execute 
    
    add-migration Report-added-newProperty
    update-database

I will get a file in the &#39;/Migrations&#39; folder adding a `newProperty` column to the table. This works fine. However, on the older entries in the database, the value for the `newProperty` is now an empty string. But I want it to be, e.g., &quot;old&quot;. 

So my question is: How do I set default values for new properties (of any type) in the migration script (or elsewhere)?

Code-first migration: How to set default value for new property?

In ASP.NET MVC 5 you could throw a [HttpException][1] with a HTTP code and this would set the response like so:

    throw new HttpException((int)HttpStatusCode.BadRequest, &quot;Bad Request.&quot;);

`HttpException` does not exist in ASP.NET Core. What is the equivalent code?


  [1]: https://docs.microsoft.com/en-us/dotnet/api/system.web.httpexception

ASP.NET Core equivalent of ASP.NET MVC 5&#39;s HttpException

As the title suggest i&#39;m having a problem with the first query against a SQL Server database using the Entity Framework. I have tried looking for an answer but no one seems to actually have a solution to this.

The tests was done in Visual Studio 2012 using Entity Framework 6, I also used the T4 views template to pre-compile the views. The database was on a SQL Server 2008. We have about 400 POCOs (400 mapping files), only have 100 rows data in database table.

Following capture is my test code and  result.

	static void Main(string[] args){
		Stopwatch st=new Stopwatch();
		st.Start();
		new TestDbContext().Set&lt;Table1&gt;.FirstOrDefault();
		st.stop();
		Console.WriteLine(&quot;First Time &quot;+st.ElapsedMilliseconds+ &quot; milliseconds&quot;);

		st.Reset();
		st.Start();
		new TestDbContext().Set&lt;Table1&gt;.FirstOrDefault();
		st.stop();
		Console.WriteLine(&quot;Second Time &quot;+st.ElapsedMilliseconds+ &quot; milliseconds&quot;);
	}

Test results

    First Time 15480 milliseconds
    Second Time 10 milliseconds


Entity framework very slow to load for first time after every compilation

Could you guide me on how to view the current roles/permissions granted to any database user in Azure SQL Database or in general for a MSSQL Server instance? 

I have this below query: 

    SELECT r.name role_principal_name, m.name AS member_principal_name
    FROM sys.database_role_members rm 
    JOIN sys.database_principals r 
        ON rm.role_principal_id = r.principal_id
    JOIN sys.database_principals m 
        ON rm.member_principal_id = m.principal_id
    WHERE r.name IN (&#39;loginmanager&#39;, &#39;dbmanager&#39;);

I further need to know what are the permissions granted to these roles &quot;loginmanager&quot; and &quot;dbmanager&quot;? 

Could you help me on this?


How to view the roles and permissions granted to any database user in Azure SQL server instance?

Table is:


| Id | Name |
|----|------|    
| 1  | aaa  |
| 1  | bbb  |
| 1  | ccc  |
| 1  | ddd  |
| 1  | eee  |


Required output: 


| Id |        abc          |
|----|---------------------|
|  1 | aaa,bbb,ccc,ddd,eee |


Query:

    SELECT ID, 
        abc = STUFF(
                     (SELECT &#39;,&#39; + name FROM temp1 FOR XML PATH (&#39;&#39;)), 1, 1, &#39;&#39;
                   ) 
    FROM temp1 GROUP BY id

This query is working properly. But I just need the explanation how it works or is there any other or short way to do this. 

I am getting very confused to understand this. 




How Stuff and &#39;For Xml Path&#39; work in SQL Server?

One of my tables have a unique key and when I try to insert a duplicate record it throws an exception as expected. But I need to distinguish unique key exceptions from others, so that I can customize the error message for unique key constraint violations.

All the solutions I&#39;ve found online suggests to cast `ex.InnerException` to `System.Data.SqlClient.SqlException` and check the if `Number` property is equal to 2601 or 2627 as follows:

	try
	{
		_context.SaveChanges();
	}
	catch (Exception ex)
	{
		var sqlException = ex.InnerException as System.Data.SqlClient.SqlException;

		if (sqlException.Number == 2601 || sqlException.Number == 2627)
		{
			ErrorMessage = &quot;Cannot insert duplicate values.&quot;;
		}
		else
		{
			ErrorMessage = &quot;Error while saving data.&quot;;
		}
	}

But the problem is, casting `ex.InnerException` to `System.Data.SqlClient.SqlException` causes invalid cast error since `ex.InnerException` is actually type of `System.Data.Entity.Core.UpdateException`, not `System.Data.SqlClient.SqlException`.

What is the problem with the code above? How can I catch Unique Key Constraint violations?

How can I catch UniqueKey Violation exceptions with EF6 and SQL Server?

**Can we run sql script using code first migrations?** 

I am new to code first and if I want to save my changes to a SQL script file before update-database command of migration, is it possible?

If possible then please provide steps to get it done. Also if script is generated then is it possible that I can run that script using migration?

Can we run SQL script using code first migrations?

Most tutorials are Entity Framework with no mention of Ado.Net in .Net Core projects. I have a &quot;legacy&quot; database, so a EF/&quot;Code-First&quot; approach is not an option.

For ADO.NET connections, is the `System.Data.SqlClient` available to an ASP.NET Core project? 

It is available when I use a .NET Framework project template but is it still available in a .NET Core project?

SNIReadSyncOverAsync Performance issue

.Net Problem Overview

.Net Solutions

Java 8 LocalDate Jackson format

How to make a simple collection view with Swift

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