I am a firm believer of a fact, that if you are not learning anything new at your work, it is time to move out of that comfort zone, pack your bags and find a gig where you will. Lately, my work shifted and consists of 99% maintenance grunt work and 1% of actual new development. In that kind of situation, a person can easily forget, that despite chewing the dog food, there is an occasional pickle here and there. So, I created this series. To remind myself, that I am still learning something new and to, hopefully, provide some extra value to whomever stumbles to this place.

So, these are the things I learned in past week:

  1. The verb INTO is not necessary when running INSERT SQL statements on Microsoft SQL Server;
  2. Direct cast of column value of System.Data.DataRow object in .NET 1.1 does not work anymore on Windows Server 2012 and Windows 10;
  3. How to compare strings with fault tolerance;

Now to details.

 

The verb INTO is not necessary when running INSERT SQL statements on Microsoft SQL Server

Debugging for some odd mishap, I have located the following piece of code:

According to SQL standard, verb insert should be followed by verb into. Except it wasn’t. I thought that this has got to be some obsolete code that no-one uses. I’ve checked references and found a few. So that wasn’t it. The code obviously worked, as it exists since 2012. So what the hell?! Well, it turns out, that even though the verb into is mandatory by standard, most implementations (Microsoft SQL server included) ignore this and keep it as optional. I am definitely not adopting this, but it certainly is interesting.

 

Direct cast of System.Data.DataRow column value in .NET 1.1 does not work anymore on Windows Server 2012 and Windows 10

Yes, I know. Microsoft stopped supporting .NET 1.1 framework with Windows 7. Still, we have some projects that run (or more accurately ran) properly even on newer Windows OS. Except that with every update to Windows 10 and Server 2012 it is more and more obvious that .NET 1.1 is getting pushed out.

The latest thing was an InvalidCastException when executing this statement:

where row is of type System.Data.DataRow. One would think that value is not integer, but in this case it was 103, which by my books, is an integer. Interestingly enough, this works:

Go figure.

 

How to compare strings with fault tolerance

In one of our projects, searching by peoples name and surname just wasn’t good enough. Spelling mistakes and different characters in place for unicode ones were supposed to be taken into account.

After 5 minutes of “googling”, I found a StackOverflow answer that suggested using Damerau-Levenshtein distance algorithm. Levenshtein’s distance algorithm provides a way to calculate number of edits that need to be done on one string to get another. Damerau-Levenshtein algorithm is an upgrade that also allows characters to be transposed.

However, this is just the first step. Algorithm provides you with a number of edits. To use it, you still need to define a threshold of how many mistakes will you allow. Fixed values are just not good, if your string length varies. So, I used half of the length of either search query or provided value. It works like a charm.