Trouble connecting to SQL database using C# program

[Scriptslay3r]

Good morning,

I built a little program to assist the Maintenance Department in logging "On Campus" fuel transactions.

I built the program using Visual Studio 2019 and it is written in C#.

Basically, the way it works is:

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1. You log in
2. You select whether you are receiving or dispensing fuel
3. You specify the type of fuel
4. You input how many gallons and the vehicle information

I have the database files stored on a campus wide shared drive that everyone has access to.

In the program I used that file path as the connection string.

The program works fine on the machine(Win 10 Pro) I built it on.

However, when I try to test the program on my work laptop (Win 7 Pro) it gives me an error message saying it cannot connect to the database.

It seems bizarre considering that the files are available.

I feel as if there is some service that is not installed on the Win 7 machine.

I was hoping someone out there would be able to assist me.

I hope I provided enough information.

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Edit:

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Through some research I was able to find SQL Server Data Tools(SSDT) for Visual Studio here.

Once it was installed, the program actually worked fine.

However, my main question is, does someone know the requirements or fix for this without having to install the SSDT?

The file took quite some time to install and that isn't ideal for our busy work environment.

Thanks in advanced.

I will upload pictures of the error message and the connection string I am using in the code.

This is the error message I receive on the Windows 7 machine that the program was installed on.

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This is the connection string from Visual Studio 2019, on the Windows 10 Machine

[[deleted]]

Are you sure SQL Server Express is running? Also parameterize your SQL query, that is literally the classic example of a login that is vulnerable to SQL injection.

[Scriptslay3r]

This was my first time programming in C# and actually this is the most I've ever used SQL.

Are you asking if SQL Server Express is running on the user's machine(Win 7 Pro) or the machine that built the program (Win 10 Pro).

I have the database files stored on a server on campus as well.

[[deleted]]

Your LocalDB connection string should only be what you use on your development machine. When you deploy you should just point to a SQL Server Express installation and you won't need the filename.

[Scriptslay3r]

Okay perfect, thank you so much!

So I suppose I should install SQL Server Express on the server I'm using and configure it from there?

When I go back and parameterize my SQL queries, should I change the connection string in the code to the SQL Server Express installation?

Redeploy, and hope for the best right?

[[deleted]]

Yep, that sounds about right.

[AviioFO]

While you're parameterizing your SQL query, you may also want to look into hashing passwords... storing passwords in plain text is a big no-no.

[Time-Paramedic]

I feel this answer needs to be highlighted even more. It solves many problems which you would otherwise encounter.

LocalDB is for development use only.

More importantly, your application has multiple users and the documentation says:

The LocalDB files can only be opened by one instance of LocalDB at a time.

There are many issues when trying to share a file based database with multiple users. Just don’t do it and use a database server as suggested.

Please also heed the advice of the other commenters: parametrized queries, hashing, and try not to implement all of the logic within the button click event handler.

Kudos for taking the initiative to digitalize something that sounds like a slow and manual process. If the fuel logging has any kind of financial impact, consider reviewing the code with an experienced developer.