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How to get the size of all MySQL Tables in all Databases (and other size-related queries)

Yesterday I was trying to investigate through an odd size increment affecting one of our MySQL databases. Since I didn’t knew about the table(s) affected by the issue, the first thing I needed to do was to take a look at each table size among the various DB that were there.

I managed to perform such analysis in few minutes with these great queries, loosely based upon those present within this StackOverflow answer.

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ASP.NET Core and Angular 2: understanding the differences between “broken code” and “compatibility issues”

It’s been six months from the first release of my ASP.NET Core and Angular 2 book and I’m very happy about the positive comments & reviews it received worldwide: however, in this post I will mostly talk about the negative reviews collected by the book, trying to figure out the reasons why they were given and saying my point of view about them.

Let’s start by looking at the numbers:

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Error TS2693 Build:’Map’ only refers to a type and other Typescript compilation errors – How to Fix

Within the past two weeks I received a lot of feedbacks from the readers who bought my ASP.NET Core and Angular 2 book for a rather nasty issue which is also affecting a lot of Typescript-based applications. This is hardly something new: Typescript is sadly full of compilation issues, expecially whithin Visual Studio 2015 and 2017. We already dealt with them a number of times in the past: TS5023TS2304 and even the “Compile on Save” feature, just to name a few.

However this one is different because it involves an internal issue within the DefinitelyTyped repository, which used by many developers to “normalize” the type definitions among different versions of Typescript, thus addressing the compilation errors themselves: in other words, more than a Typescript bug we’re dealing with an internal issue of a useful workaround.

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Merge multiple GIF, PNG, JPG, TIFF and PDF files into a single PDF file with ASP.NET C# using the iTextSharp library

Yesterday I released a small project I was working on to merge multiple image files into a single, multi-page PDF (one image per page). It wasn’t too difficult, yet I had to deal with the following issues:

  • Some nasty GDI+ issues when dealing with multi-page TIFF files (read this post for further details on that).
  • Some nasty GDI+ issues when trying to resize/resample each image to make it fit to the container PDF page size.

Yeah, you can easily guess I really don’t like GDI+. Luckily enough, I found a great open-source alternative to deal with these issues: I’m talking about the iTextSharp library, freely available through NuGet or SourceForge, which can flawlessly do these kind of tasks.

Using it proved to be really simple; here’s what I did to fullfill my specific scenario (WARNING! big amount of source code incoming):

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ERR_BLOCKED_BY_XSS_AUDITOR error in Google Chome – How to fix it

With the recent Chrome 57 build, the XSS auditor detection (and blocking capabilities) has been improved to the point that many web-based services suddendly stopped working giving this rather obscure HTTP error:

ERR_BLOCKED_BY_XSS_AUDITOR

The issue is almost always caused by some HTML-formatted content being sent via POST within the request, which is a rather common behavior for a number of modern web tools and features – such as WYSIWYG editors, interactive uploaders, AJAX-based CMS real-time updates, and so on.

When the tool is developed by third-parties, the best thing you can do is to open an issue with the developers and make them go through the hassle: however, there are scenarios where you *need* to anticipate the fix by yourself, not to mention the cases when *you* are the tool developer. This is what happened to me yesterday, when I had to apply a quick fix to a tool I coded for a friend of mine a while ago: an interactive electronic invoice display which follows the recent italian electronic invoice PA standards. (more…)