Delphi Tip of the Day - First Chance Exception

[DP News-Robot]

I'm in the process of upgrading a very old Delphi program that I wrote with my Turbo Pascal, top-down, structured-programming, mindset. One of the major updates I want is for the data to be in a database. So, I'm cruising right along making very good progress. After two days I finally get the algorithm working. And it's producing good results.

Now it's time to get those results into a database table. No big deal. FDMemtable and LocalSQL will do the trick. I'll just add a DataModule to the project. Drop in the necessary components. Add the fields using the fields editor.

I get everything working in the IDE. I'm good to go. All I need to do now is add the SQL. I code up the insert statements. I'm very excited. I will soon have the data in a database table. I push F9 and... BOOM!

"What the hell is a First chance exception?"

You've got to be kidding. I was so close. I started googling all over the internet trying to figure out what a First chance exception is. I just wanted an answer. After an hour or two I gave up. I was tired. I was frustrated. I'll deal with it in the morning. Off to bed I went.

"It turned out to be a very simple fix!"


The next day with a fresh attitude I returned to my project. It turns out this was a very simple fix. I didn't see or think about this the night before. When I added the DataModule to the project it was added to the bottom of the list.

The OnCreate method of Form1 calls the logic in another unit, which in-turn communicates with DataModule1. Because the DataModule1 is created after Form1 gets created it caused an exception. All I had to do was move the DataModule1 before Form1.

I literally had the cart before the horse. I remember getting burned by this in the past but totally forgot about it.

Enjoy!
Semper Fi,
Gunny Mike

Feedback is always appreciated.

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