Assign Variables from MySQL Database Field

[Vladamir]

I'm looking for a method to assign dynamic variables by using the column names from the MySQL database.

   dbread = dbcomm.ExecuteReader()
            While dbread.Read

                  ' Me.controls("Label" & i.ToString).text = leg.GetValue(0).ToString
                  Me.controls(dbread.GetName(i)).text As String = dbread.GetValue(i)

            End While

I think this can be done just need a little more advice. What we want to end up with is the column names from the MySQL database become the variable names and the values in the field get assigned to the variable. I'm told this can be done.

[bensonsearch]

Hi,
Maybe something along this line of thinking?

Dim variables As New Dictionary(Of String, String)()
variables(dbread.GetName(i)) =  dbread.GetValue(i)  ' Set the value of the "variable"

Dim value As String = variables(dbread.GetName(i))  ' Retrieve the value of the variable but with column name not dbread, unless u wanted to again

[techgnome]

I don't think that's quite what he's looking for...


@vladamir - did you try your code? did it work? Did it not work? If the name of your controls matches the name of your columns (which I think is what you're looking to do), it should work, IF the control are actually directly ON THE FORM... if they are on a panel, or other container, like a tab or something, then it won't... but only because you're only accessing the form's control collection... you'll need to know what parent the target control is on, and pull it from that control's control collection.

An alternative is to create a controls collection of your own using a Dictionary, looping recursively through all controls, adding them to your collection, usting the control name as the key. Then you could use that dictionary to retrieve the control back and use it.

-tg

[Vladamir]

Thanks again everyone. And no I did not test my code...because another developer wrote it and she said it will not work....gee thanks for that. Plus she likes to work with Form Applications thus she's always using controls, etc... This project is a console application which just talks to either other software, a database or a machine out in the shop. No user input allowed. I have to do so much of this kind of automation I'm thinking of starting a new company called NUIA which stands for "No User Input Allowed".

There is another developer here who specializes in php and he showed us how he does it. To be sure I explain this carefully he basically does his query on the database and then using the names of the columns he assigns those as variable names...not the values of those variables. The values for those variables are then picked up and assigned to the appropriate variables. So in essence he's using the output of his query to create new variables.

[bensonsearch]

Hi Vladamir,

Would that not be like my example? its really the ones why to name a variable outside of code. In PHP most likely he would use an associative array which is basically the same as my answer, the first part is the name(or key in PHP) and the second the value. the PHP one is here: http://www.php.net/manual/en/language.types.array.php example number 3.

otherwise im clearly not understanding what you mean

[techgnome]

Ben - yeah... okay... now that I see vlad's explanation and re-read what you did... yeah, using a dictionary is probably as close as you're going to get to that. It's not quite the same as what you can do in PHP ... but it's as close as you're going to get. I guess it's the difference between a script language where you can get away with that, and more typical languages where they are run through a compiler.

the only down side is that everything in the dictionary has to be the same type. which is probably largely ok, but it can suck if any of them are numbers which need to be used for calculations... then you may run into issues.

-tg

[bensonsearch]

You may run into issues but could always just try parse or isnumeric the value to check. PHP still runs through a compiler in order to be shown its just not pre-compiled, however yes PHP allows a fair bit leway.

I guess this is probably more closer to a PHP $_SESSION variable than it is an array.

[Vladamir]

Thanks again everyone. I'm thinking like you that it's time for me to sharpen my skills using Dictionaries. And as for numerics, this will all be strings, because we're simply looking to establish names for the variables. The values for those variables are mostly strings. And like I'm finding as we develop this project, whether it's a string or numeric value, we simply do the needed conversion(s) when needed. .ToString(), Convert.ToDouble, etc....

And we have a full blown web developer working with us this time. He's built some big apps for major retailers and commercial property managers. His skills with .NET are limited but his knowledge with Ajax, Java and php are proving invaluable for the user interfaces.

And beasonsearch... I live in Miami. And they serve what's known as Cortaditos (Cuban Coffee) here. Thus:

If energyNow < 40 then
Call cortadito
energyNow = 10^6
End If

[bensonsearch]

And beasonsearch... I live in Miami. And they serve what's known as Cortaditos (Cuban Coffee) here. Thus:

If energyNow < 40 then
Call cortadito
energyNow = 10^6
End If

I'm thinking its time to move me and the wife to America, especially near this Cortadito My wife is addicted to coffee or something ;P