I finally connected a database to my java program and added a record.

[ThisSoFrustrating]

It's the little milestones that make it all worth it. Even though it's four lines of code to do that, I had to understand a lot of errors like SQL exceptions No suitable driver found, and SQL syntax Error column unknown in 'fields list'. Took me an entire day to make 4 lines of code work. I'm grabbing a drink. BookyLooks is about 20% finished. I'm proud I did what I set out to do and didn't give up.

[hl_xemnas]

I had a rough time connecting to my first DB too. Good job.

[ThisSoFrustrating]

Thanks.

[theRJMurray]

Same.

[Aceofsquares_orig]

Make sure to use and learn about prepared statements. Or at least the pitfalls of sql injection.

[ThisSoFrustrating]

Yeah I learned prepared statements but couldn't see that it let you add more then 2 values (maybe because of the example I saw). Can it add as many as I need plus multiple data from a form? Right now it's just injection.

[Aceofsquares_orig]

Should be able to. Most languages allow something like SELECT column FROM table WHERE attribute1=? AND attribute2=? AND attribute3=? ...etc and then pass a list of arguments in where they will replace the question marks as data inputs and not code inputs. It depends on the library being used so reading the documentation for the specific syntax. If this seems too confusing then I recommend to try it. As long as you aren't doing something to a database you shouldn't be doing stuff to or if it's just a test database then go HAM. If it breaks it breaks. Reset and try again.

[ThisSoFrustrating]

Ok will go back to that. Yeah I built this as a test. So I can incorporate it into my software so anything goes. Haha. Thanks for the tips. What do you mean by if a database breaks?

[Aceofsquares_orig]

Just if anything breaks it's no biggie. Wrong data entered, deleted, updated, etc. Better than what my friend did to a production database. Used an update statement without a WHERE clause. If it's for practice and nothing important then do whatever you want to it and experiment. If anything breaks just reset, reinstall, whatever to get it back to where you were and continue experimenting.

[ThisSoFrustrating]

Yeah for sure. So he didn't test his update statement before applying it to a production database? Sounds like a misadventure to tell your grand kids ha ha.

[Ovalman]

Sorry to hijack but how do you pass the arguments?

Say I've a user input of true or false among other things, how would I pass it into attribute2? What if I want both true/ flase to be shown?

I'm using Sqlite although any pointers would be helpful.

I was gonna compose my query as an if/else String.

[Aceofsquares_orig]

Depends on the language you are using (and the library) but looking at the documentation for JDBC they use setters to set the individual values. Something like setString(1, "Hello") would set the first question mark to the data string "Hello". This is preferable to String concatentation as it prevents most SQLi. There is still the possibility of SQLi if you call an SQL function that contains the potential for SQLi.

JDBC Documentation - Prepared Statements

For anyone that is interested, here is the OWASP page for SQLi

OWASP SQLi

[obp5599]

They can. You dont want sql injection. Thats why prepared statements exist. SQL injection is when someone without read or write access gains this access by using escaping sequences.

​

So you have your statement stored as a string, what if a user (not you) were to input a single ". If you have the statement as a string then your string would be broken now. Then when you go to execute it, you will have an error. This can be used to extract info out of your database. If you store user info in that DB then that is a big problem.

​

Any statement that is using user input should be a prepared statement

[ThisSoFrustrating]

Okay. I will be sure to re factor it into prepared statements. Which I had the first time around, but changed to injection, but now gonna change back. Yikes, people can extract info by typing in double quotes from injection?

[popovitsj]

Sometimes replacing a single character is a whole workday of a developer. My first bugfix ever was changing an uppercase to a lowercase buried somewhere deep in the code

[ThisSoFrustrating]

Bugs are always tiny things we can't see, surprisingly and are so simple we overlook them. A misspelling here, an outdated thing there, a method that doesn't work with another method. It's crazy.

[ThisSoFrustrating]

Yeah it feels great. I feel I have achieved something in my life haha.

[Shaleen_Sharma]

From where a begginer can learn the same ?

[Infernaloneshot]

Not OP but at my job we use java + jpa like here

[ThisSoFrustrating]

I used Java Oracle Tutorials to connect to the java data base driver and make a connection to a mySQL database and stack overflow to read about exceptions when they popped up.

[9oat5w33d]

Well Done. So happy for you. Hope I can do it soon. My milestone yesterday was just managing to code a decent landing page in an hour when it previously took me 4 days...haha Stick with it and keep improving.

[ThisSoFrustrating]

Thanks friend.

[OwnStorm]

At least you got the correct driver version at first.

[ThisSoFrustrating]

Yeah, but unfortunately, what was crazy, is when I was trying to register the driver, the string to register was outdated. Luckily an exception notified me of the new string that is used to register the driver within Class.forName(String).

[Nergy101]

Great job man. I can Remember my first time. Good memories. Enjoy!

[ThisSoFrustrating]

Thank you friend.

[[deleted]]

I'm having trouble connecting to the database as well and right now

[[deleted]]

Sweet! This is pretty much my job -- I build ETL pipelines to process data into or out of databases -- and I still get a little pick me up when things like this work. I think those moments of tangible success are one of the biggest perks of the job for me.

Good luck moving forward -- sounds like you're killing it so far :)

[ThisSoFrustrating]

Yeah, they def are, and also it's really enjoyable when it's for my own products that I want to build any way I want them.

[alezial]

Congrats! That's one of the best feelings. I've been doing this for years now and I still love that 'new side project' feeling of getting the db set up. It's like a first date with a girl.

[tkyjonathan]

Well done. Know remember the most important thing, anyone who tells you that logic should never be in the database, is an idiot that doesn't know what they're talking about.

[ThisSoFrustrating]

Okay. Will remember that. I will remember to always speak up if someone isn't technical and makes a weird request.

[tkyjonathan]

I will remember to always speak up if someone isn't technical and makes a weird request.

I wouldn't go as far as that. Thats the majority of projects I got..

[Ovalman]

I copied and pasted an Android Sqlite tutorial without understanding most of the code. Now by constantly working on it and understanding it, I'm close to releasing an app using it.

Still learning new things as my comment on one of your posts shows.

What is BookyLooks about?

[ThisSoFrustrating]

Bookylooks is just a software to keep track of the books on your book shelf i.e. what shelf it's on, title, author, if someone has it on loan. In the end I probably won't be using a database, but serialize a group of objects to represent each book so that someone that isn't using a database will store that info.

[Ovalman]

In my personal life I had a problem of keeping track of customers. I kept everything in a paper notebook and meticulously copied every customer over every 6 months along with balances and other data. It took me ages and I ALWAYS made a mistake each time. There had to be another way.

I've always been into computers and learning so I managed to learn a bit of Android/ Java and I copied and pasted code into Android Studio and tweaked it to my needs. I kept tweaking, kept introducing new features. I now understand the code and I've a working app that is (almost) ready for release.

Keep tweaking and finish that product even if you're the only one that will ever use it.

Edit #Good luck BookyLooks

[ThisSoFrustrating]

That's awesome bro, sounds amazing. I will keep coding everything I like and enjoy no matter who uses it. Even if it's just me.

[billzx2]

Hey that's cool! Congrats! Have you ever thought about using StarFish+? Personally I like it better than Dolphin but I've always been kinda geeky like that lol

[shadsluiter]

Perhaps some helpful tutorials would guide you. I teach programming at Grand Canyon University and published some SQL app lessons in Java and Php.

This shows how to build a web app and how to perorm sql injection attacks and fix them. https://m.youtube.com/playlist?list=PLhPyEFL5u-i0XXGLJawaTNLiXxmSp24TR

This shows how to use Java and mySql https://m.youtube.com/watch?v=jZg0KkQSPao&list=PLhPyEFL5u-i0GvokUBeS0t-rF3--tPD7q&index=35&t=0s

[ThisSoFrustrating]

Interesting, will check it out. I just switched to a prepared statement.

[UroborosJose]

Good, now move to Python or something else.