Diary of A Developer

Every database developer using T-SQL will agree that the Select ... As feature allows one to easily grab values into a variable. However, after I got my fingers burnt recently, I had to share this to remind everyone how important it is to exercise prudence with its usage. Given the table below, assuming its an SQL table named Students. Id Name Age Class 1 Fade Ayomi 10 5 2 Oluwayomi Ojo 9 6 3 Kemi Mide 8 4 And given the SQL statements below which performs certain operations on the table given above declare @ StudentAge int ; select @ StudentAge = Age from Students where Id = 1 ; set @ StudentAge = Age * 2 ; select @ StudentAge = Age from Students where Id = 5 ; select @ StudentAge as AgeSelected; So what would AgeSelected resolve to according to the provided information? Ordinarily, one would expect AgeSelected to be NULL however, since @StudentAge carried a value initially, and the row described in the where clause do not exist in the table, @Stud...

Background: I use CorelDraw a lot to lay out my reports before writing the iTextSharp code to generate them. It gives me a fair idea of how to position report elements and keeps me from doing guesses or trial and error. This was the case when I worked on the ID Card project for Delta State University: I had the ID card neatly laid out and the school loved the design. Issue: Now, everyone knows we normally have long names in Nigeria. My design template had a name that was 10 characters long and I used 28pt points for this text. What I wanted to achieve however is that, for names that will not be able to fit into the maximum space allowed for the name text at the 28pt used in the design template, the system should use the maximum font size that will permit the name to fit in the space available. Its a simple problem, but wasn't so easy to resolve. Solution: public Font GetSafeFont ( string DisplayText, Font FontToUse, float SafeLength, float StartingSize) {...

With the magical things developers can achieve with JavaScript these days, there is almost no reason to develop on the web without JavaScript. The drawbacks of the traditional web development approaches are just too unbearable. JavaScript introduces superb user experience with AJAX and developers can now update an element on a page without post back! Although JavaScript solves  most of the developer's head ache, it introduces its own issues. Foremost of these are security flaws of which we have the 3 giants: XSS, CSRF and SQL Injection. I remember implementing a solution for a leading financial company in Nigeria, and though I insisted on stringent security measures for the Web API, the guy in charge maintained that there was no need for it, and the project went ahead without it. Yes! there are lots of systems trusted by the public that are in use without adequate security. I'm afraid these are time bombs waiting to explode. The effect of not adequately securing a syste...

Background: I just recently upgraded to Windows 10, and I must confess, the overall experience immediately got me. I love the fact that our good old start menu was back and better. The tile one was much of a controversy although I have been indifferent about it all the while. I particularly love Cortana, the search assistant who made me remember the office assistants that used to come with the office suite back then. The euphoria I experience was a perfect disguise, however, for the ambush that was ahead. Issue: I went ahead to open VisualStudio and launched the project I was currently working on. I pressed F5 to launch it, only to ram into a jam! The project I still successfully tested only a day before now threw an exception. From my experience, and this situation hasn't proved me wrong, every Microsoft upgrade always has a catch somewhere. This particular one forced me to begin to rectify a fault in an application that was initially 'bug-free' before my u...

Background: After surmounting my last challenge with dropzone.js and was able to upload my files. I was immediately faced with another one. The dropzone.js implementation apparently doesn't include any method for computing a value to send to the server while the file is being uploaded. What this means is that any headers or form data used to initialize the dropzone will be used repeatedly each time a file is uploaded. Issue: This meant that, for instance if I didn't want to upload a file using its name from the client, I may not be able to specify another name for the file as it is being uploaded. And that was exactly what I was faced with. Each time I created another record and uploaded a corresponding file with the dropzone, the file would overwrite my previous files, because I was apparently sending the same custom filename to the server to save my files with. My dropzone initialization code looked like this var mydropzone = $(targetelement).dropzone({     ...

Background I found myself in this mess. I wrote a lovely windows service to handle data replication between two SQL Servers. I know this isn't the best way to go about it, but the requirement came in late into the project and the database design wasn't going to support automatic replication provided by SQL Server, so I had to develop this windows service. Unfortunately, I lost the source code and backup in a robbery incident and I'm left with just the compiled version deployed with a client. Issue A bug showed up which needed to be fixed, but I didn't have the source anymore. I would have had to go through the stress of re-writing the entire code which took about a month to complete initially if I didn't run into this solution. I'm feeling great right now! Solution It happens that there are a couple of projects targeted at de-compiling .NET codes. I found two: 1 .NET Reflector 2. Just Decompile I tried the .NET reflector and it worked like m...

Issue Sometimes in web development, we may want to grant WRITE access to a folder probably for file upload purposes or mostly in my own case, PDF file generation purposes. The challenge however, is that all folders are read only which means your application will always throw errors whenever you attempt a write operation. Solution Locate the folder in windows explorer Right click on the folder and select properties In the securities tab, click edit, then click add in the new dialog box that shows up Type IIS AppPool\ApplicationPoolName (you need to replace ApplicationPoolName with the name of the application pool in IIS that your web app is running under) Click Check Names to resolve the name, then click Ok  Under permissions for ..., check Modify under allow.  Click Ok on all dialog boxes Note Some people will grant Modify or Full Control right to Everyone for the folder, note that this posses a huge security risk and should never be your approach to r...