In my application I import files, process them and save them to the database. This leads to large amounts of inserts and updates on the database. It can be very frustrating to have Entity Framework reject all update with a message: “The conversion of a datetime2 data type to a datetime data type resulted in an out-of-range value. “.
This message usually means a DateTime.MinValue is being inserted into a SQL DateTime column. The problem is to figure out which entities are causing the problem.
To help with this I wrote some code to inspect the pending changes. Luckily me and my team have been consistent when it comes to using “Date” in a property name wherever applicable.
// first get all the changes (added or modified)
var changes = MyEntities.ChangeTracker.Entries().Where( x => ( x.State == System.Data.Entity.EntityState.Modified ||
x.State == System.Data.Entity.EntityState.Added )).ToList();
// look for all changes involving date field
var entitiesWithDate = ( from c in changes
where c.CurrentValues.PropertyNames.Where( pn => pn.Contains( "Date" ) ).Any() == true //
select c ).ToList();
// select all entities where datetime value is before 1/1/1000 which will be rejected by SQL Server
// I use 1/1/1000 because DateTime.MinValue did not seem to work
var entitiesWithMinValueDate = ( from e in entitiesWithDate
from p in e.CurrentValues.PropertyNames.Where( pn => pn.Contains( "Date" ) )
where e.CurrentValues[p] != null && (DateTime) e.CurrentValues[p] < new DateTime( 1000, 1, 1 )
select e ).ToList();
Notice I put #if DEBUG around the code, we don’t need this unless we’re debugging.
After working on a new website yesterday I was ready to share my progress with some friends and I was dismayed that the link produced on Facebook was not pretty, the way other site are automatically linked with a nice picture and the right kind of info. Not to be discouraged I figured I had to do better…
The Open Graph Protocol
A little searching led to the Open Graph protocol: “The Open Graph protocol enables any web page to become a rich object in a social graph. For instance, this is used on Facebook to allow any web page to have the same functionality as any other object on Facebook.”
So in other words: the regular meta tags I was using were not helping I needed to add ogp.me tags.
There is some help on page, but a basic example for your homepage is not on the OGP.ME webpage so I figured I’d share my result:
<meta property="og:title" content="Chianso: digitaal kindvolgsysteem, documentbeheer en kinddossier." />
<meta property="og:type" content="website" />
<meta property="og:url" content="https://www.chianso.nl/" />
<meta property="og:image" content="https://www.chianso.nl/Images/ChiansoLogoShareX256.jpg" />
<meta property="og:site_name" content="Chianso" />
<meta property="og:description" content="Chianso biedt een digitaal kindvolgsysteem, online documentbeheer en digitaal kinddossier waarmee voldaan wordt aan nieuwe IKK regelgeving, kwaliteitsverbetering op de groep en kostenbesparing door het terugbrengen van administratieve handelingen." />
<meta property="og:locale" content="nl_NL" />
Now what I found is that the image you want to share cannot be larger than 8MB, also, even though I found no documentation for this, JPG images seem to work better than PNG.
So one way of getting this right is adding the info to your website and the trying to share a link on Facebook. This will work once… then the next try may not show any of your changes. A very useful tool at this point is the Facebook Debugger. It will load all the metadata from your site and provide a link preview. Together with a bunch of hints and useful info AND it offers a ‘Scrape Again’ button, which invalidates the caching that is in play.
You can find the debugger here: https://developers.facebook.com/tools/debug/sharing
I recently upgraded all projects in a solution to .NET 4.7 and started seeing some NuGet warnings:
Essentially what seems to happen is that the NuGet package was installed when .NET 4.6 was the runtime target and this package may or may not need to be reinstalled (everything was functioning, but I just don’t like warnings when compiling).
Turns out there is no UI button for reinstalling a package, so the Package Manager Console is the place to go. The following command will reinstall the appropriate package for all project that use the package:
Update-Package -Id <package_name> –reinstall
Note that as soon as you’ve typed -Id you can use <Tab> to get a drop down list of installed packages.
For more variations of the command see: https://docs.microsoft.com/en-us/nuget/consume-packages/reinstalling-and-updating-packages
I used to have active work item tracking turned on in my Solution Explorer, but that can get annoying, so I turned it off, but then I found I spend too much time searching for my active document. I figured there must be an easier way. Sure enough, Visual Studio has got me covered on this…
So, active item tracking is set in the configuration settings:
As you see, I have turned it off.
Now when you have an active document open in the editor, the Solution Explorer will start a bi-directional arrow icon:
Press it to have the solution explorer track down the active document in the solution explorer. The feature is called ‘Sync with Active Document’. Also accesible via keyboard shortcut: CTRL+[, S
I’ve been working on an Entity Framework Code First solution using an Azure database. The migrations work like a charm, but often I’d like to recreate the database from scratch and re-seed from scratch. DropAndRecreate does not work due to permission issues, so the next best thing is to drop all tables in the database and use Database-Update from the Package Manager Console to recreate the database.
I use the following scripts to drop every constraint and then every table:
while(exists(select 1 from INFORMATION_SCHEMA.TABLE_CONSTRAINTS where CONSTRAINT_TYPE='FOREIGN KEY' and CONSTRAINT_SCHEMA != 'sys'))
declare @sql nvarchar(2000)
SELECT TOP 1 @sql=('ALTER TABLE ' + TABLE_SCHEMA + '.[' + TABLE_NAME + '] DROP CONSTRAINT [' + CONSTRAINT_NAME + ']')
WHERE CONSTRAINT_TYPE = 'FOREIGN KEY'
while(exists(select 1 from INFORMATION_SCHEMA.TABLES where TABLE_SCHEMA != 'sys'))
declare @sql nvarchar(2000)
SELECT TOP 1 @sql=('DROP TABLE ' + TABLE_SCHEMA + '.[' + TABLE_NAME + ']')
WHERE TABLE_SCHEMA != 'sys'
After which I use the Package Command Console to run:
Update-Database -ConnectionStringName AzureDevTest
Since the migration history table is missing it will run all the migrations.
The feature is ancient and you would think I would always remember, but just as a reminder to myself and to help those that don’t know:
When you’re logged into a remote machine using a remote desktop session and you want to change your password on the remote machine, use CTRL-ALT-END to see the change password option ( so END instead of DEL ).
I’m working on an app that at some point will need to work in multiple languages and needed to display the day of the week to the user. I started with:
string label = DateTime.Today.DayOfWeek.ToString()
But that give me the name of the enumeration, which is of course in English. In order to get the name based on the current language setting I needed the following code:
var culture = System.Globalization.CultureInfo.CurrentCulture;
string label = culture.DateTimeFormat.GetDayName(DateTime.Today.DayOfWeek);
Sometimes it is all about knowing Powershell is ready to help: I was messing around with creating a script to archive a folder into a zip file when I discovered the Compress-Archive command in Powershell:
Compress-Archive -Path "c:\sources" -DestinationPath "c:\sources.zip"
Sometimes simple things are hard to remember, so if you ever want to enter a null value when editing table data using SQL Server Management Studio, then remember that there are 2 options to do it:
- Copy and paste a NULL value from another field;
- Enter CTRL+0 (control zero).
In the last 2 weeks I’ve upgraded two (large) C# / ASP.NET solutions from Visual Studio 2015 to Visual Studio 2017. Good news? By and large things ‘just’ work. But there were three things that required attention:
- Issue: My project used PowerShell projects from “PowerShell Tools for Visual Studio 2015“. This VS2015 extension did not automatically get activated for VS2017.
- Download and reinstall the extension. The installer recognized that VS2017 was now installed and enabled the extension for VS2017.
- Issue: The projects were both using the Microsoft Unit Test framework and the unit test runner would run without issue in VS2017, but Live Unit Testing would not work.
- In the Unit Test project(s) remove the reference to: Microsoft.VisualStudio.QualityTools.UnitTestFramework.dll
- Use nuget to add MSTest.TestAdapter and MS.TestFramework to the unit test project:
- Issue: My Team Services CI build failed after I started using C#7 syntax in my code.
Solution: Install Visual Studio 2017 on the build server and change the build definition to use Visual Studio 2017 for building the solutions.
Alas, this will not (yet) work if you’re using a Hosted Agent. So be sure to be using a build agent that runs on a machine where Visual Studio 2017 is installed.
Useful to know:
- For a short time some team members were working with VS2015 and some with VS2017. No problem as long as you’re not using C#7 syntax just yet 🙂
- Play around with including/excluding tests from Live Unit Testing, for larger solutions the performance hit of having all the tests being run all the time seems prohibitive.