Issue with CRUD operation DELETE in java

[static linden]

hi guys! i would really appreciate help. so as you can see in the picture im getting error "No value specified for parameter 1" when im trying to delete one row in database through button in java gui application. i think the problem is in query - but i am not sure. i have quite a lot of rows in my database (im working in mysql) and through button in java gui i want to delete any row that i want. when i specify the id for example "100006" in query it deletes the row, but i want to be able to delete any row that i select. thanks!

[ocean rampart]

<@&987246584574140416> please have a look, thanks.

[ocean rampart]

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[unkempt aspen]

you need to specify the value of the argument of the sql statement

you did ...=?

you have to give a value for the "?"

otherwise how can it knows what to select ?

[static linden]

yes but i dont want to specify the id

i want to delete any id that i select from application

[unkempt aspen]

wdym

[static linden]

wait let me show you

[unkempt aspen]

how can it knows what to select if you don't tell it that ?

[static linden]

when i click on this button i want the whole row to be deleted

but i have other rows too in my databse

database*

[unkempt aspen]

yes ?

[static linden]

when i click on it it gives me that error

this is my database

i dont want a specific row to be deleted like for example the 10006 one

i want to be able to delete row thats selected in application

i hope that makes more sense

[unkempt aspen]

then get the id of this row

and set the ? as this id

[static linden]

that works yes but thats not what i want

i wanna be able to delete row of the selected recipe in application

i have quite a lot of recipes in my application

so whenever i click "delete" it should delete any recipe that i selected in app

not just specific one

[unkempt aspen]

then what's the problem ?

get the id of the recipe you selected

and then do the request with it

[static linden]

but i have to do it without changing the code

i shouldnt specify id in the code

i should be able to delete any row

[unkempt aspen]

wdym

you associate an id to each row

so when someone click on a row

you get the id back

and do the request with it

what do you not understand here ?

[static linden]

how do i write that in the code?

[unkempt aspen]

you probably coded the rows like

class Row {
int id;
...
}

then when you click on the row

you do int id = row.id

then you create the request

and then you do

ps.setInt(1, id);

and then you execute the request

[static linden]

i havent coded the rows theyre made through database

[unkempt aspen]

wdym

what is the type of the rows ?

[static linden]

int

id is int

[unkempt aspen]

?

what's the problem then ?

[static linden]

this is the table

in my database

[unkempt aspen]

yes

[static linden]

it gives me that error parameter

because the query is not correct

what should i write in query?

[unkempt aspen]

yes it isn't

you are supposed to give a value

[static linden]

i understand that

what value?

if i wanna delete any row

[unkempt aspen]

the value that will replace "?"

[unkempt aspen]

all rows ?

[static linden]

every row has different id

[static linden]

nope

[unkempt aspen]

which row ?

[static linden]

every row has different ids

[static linden]

selected one

in app

[unkempt aspen]

what does selecting give you ?

[static linden]

i mean pressing the button

when you click "delete" on some recipe it should delete it

from database

[unkempt aspen]

what is the type used to represent the rows ?

[static linden]

what type*

?

[unkempt aspen]

how do you represent the rows in your app ?

did you create a row class ?

[static linden]

nope

i made thru gui app

obriši means delete

[unkempt aspen]

then what did you use ?

[static linden]

and basically that what you see is what is in database

[static linden]

gui

[unkempt aspen]

yew but which type ?

[static linden]

window builder or idk

[unkempt aspen]

which type

how do you represent the row in the gui

[static linden]

oh

text field

[unkempt aspen]

and for the id ?

same ?

[static linden]

and text area for larger ones

[static linden]

there is no id to be shown

in app

[unkempt aspen]

wdym

[static linden]

only name, ingredients and preparation of recipe

i didnt put id to be shown of recipe in the app

[unkempt aspen]

even if you don't show the id

you still have to store it somewhere

[static linden]

in database

its integer

[unkempt aspen]

no

in your app

[static linden]

wait

[unkempt aspen]

you need to store the id of each row you display in your app

[static linden]

oh

well i havent done that?

[unkempt aspen]

yes

so do it

[static linden]

so how do i do that?

[unkempt aspen]

create a variable

[static linden]

and when i create it what after it?

[unkempt aspen]

when you display the row

when you set each text field

you also set the variable to the id

[static linden]

do i really have to display id?

[unkempt aspen]

no

[static linden]

alright

thanks for help anyway

[static linden]

hi sorry to bother you but i did what you said but it doesnt work

when i click on delete nothing happens

[spice spire]

ull have to share ur code again. otherwise it's impossible for anyone to help u

[static linden]

sure

JButton btnNewButton_2 = new JButton("Obriši");
btnNewButton_2.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
int action=JOptionPane.showConfirmDialog(null, "Do you want to delete?", "Delete", JOptionPane.YES_NO_OPTION);
if (action==0) {
try
{
Class.forName("com.mysql.cj.jdbc.Driver");
Connection con=DriverManager.getConnection("jdbc:mysql://stnt.vri.hr/aaa?serverTimezone=UTC", "aaa", "11");
String upit3="DELETE FROM recept where sifra_recepta=?" ;
PreparedStatement ps=con.prepareStatement(upit3);
int sifra_recepta = 0;
ps.setInt(1, sifra_recepta);
int obrisano=ps.executeUpdate();

             if (obrisano>0)
             JOptionPane.showMessageDialog(null, "Obrisano");




             }

             catch (Exception e2)
             {
             System.out.println(e2);
             }
            }
        }
    });

[ocean rampart]

Detected code, here are some useful tools:

Formatted code

JButton btnNewButton_2 = new JButton("Obriši");
btnNewButton_2.addActionListener(new ActionListener() {
  public void actionPerformed(ActionEvent e) {
    int action = JOptionPane.showConfirmDialog(null , "Do you want to delete?", "Delete", JOptionPane.YES_NO_OPTION);
    if (action == 0) {
      try {
        Class.forName("com.mysql.cj.jdbc.Driver");
        Connection con = DriverManager.getConnection("jdbc:mysql://stnt.vri.hr/aaa?serverTimezone=UTC", "aaa", "11");
        String upit3 = "DELETE FROM recept where sifra_recepta=?";
        PreparedStatement ps = con.prepareStatement(upit3);
        int sifra_recepta = 0;
        ps.setInt(1, sifra_recepta);
        int obrisano = ps.executeUpdate();
        if (obrisano > 0) JOptionPane.showMessageDialog(null , "Obrisano");
      } catch (Exception e2) {
        System.out.println(e2);
      }
    }
  }
}
);

[static linden]

what does this tell me?

when i click on button "delete" absolutely nothing happens

it doesnt even give me the error

[sweet dust]

check in your db that it gets erased, if there is no error, then something has happend

[static linden]

it doesnt get erased

[sweet dust]

try to printout the actual sql query to see that it's correct, and try it in the db

just to rule out one side of the operation

[static linden]

it doesnt work

[spice spire]

its for us to be able to read ur code. since u posted raw unformatted code. which is absolutely unreadable to any helper

u can learn how to post it properly urself by reading the explanation by the bot when u started ur thread

[spice spire]

we can't help u like that. u have to work with us, give us details, Screenshots, document what ur doing and seeing,...