Update values in a cell of a JTable - java

I want to put subject results in a Jtable. I set DefaultTableModel to the table. In my table I have three columns.Student ID,Marks and Grade.Student ID is auto generated in column one.then user should enter marks for for second column.Then I want to automatically put the necessary grading in 3rd column.I load the grading data from the database and find the correct grading for the marks.I try this with both MouseReleaseEvent and KeyReleaseEvent.But it wasn't successful.Can any one suggest me a better way.thank you.

You don't have to listen for the input events, because the table has cell editors already. So you should be capable of editing your table. The only thing you need to do is to listen for the tableChanged event and update the database there.
See: TableModelListener
In case I was confused by your thoughts about the events and you just want to basically set values of a cell programmatically, try this method: setValueAt(Object,int,int)

Related

Update mysql when cell value is edited in JTable

Well I have a JTable in my app that fetches records from a MySql database adn displays them in a sorted order.
Till now I have been using a separate JTextArea and a JComboBox to allow the users to edit the table, something like
so whenever someone clicks on a row in the table the ID of the record is automatically updated below in a JLabel that lies before the JComboBox.
The question is how can I allow users to simply double click and edit values in the cells which would automatically fire a SQL Update query and update the same in the database. I want to allow this on certain Columns only not every Column.
A response with a code example would be highly appreciated.
how can I allow users to simply double click and edit values in the cells which would automatically fire a SQL Update query and update the same in the database.
You can use a TableModelListener to be notified of changes to the TableModel.
I want to allow this on certain Columns only not every Column.
The row/column is found in the TableModelEvent so you check the column that changed before invoking the SQL update.
One potential problem with this is that a TableModelEvent is generated even if the data isn't changed. That is if you place the cell in edit mode and, for instance, tab to the next cell without change the data and event will still be generated.
To get around this problem you may want to consider using the Table Cell Listener. When using this class the event is only generated if the data has actually been changed.

(Java) Jtable Operations and Exceptions

I just got this Jtable on Netbeans . First I want it to auto-calculate some grades, as you can see it has 3 columns (1st, 2nd and 3rd evaluation). I have to type between 0 and 100, in each row.
In the end, get the total and average. This can be displayed in a Jlabel, or a textfield. But, it has to be displayed real-time (as I'm typing the values).
Also, I can't type data on all the cells, just one for each row. How do I do this?
I know I can change the columns to accept only Integer values, but for everything else, I have no idea how to proceed.
In the end, get the total and average. This can be displayed in a Jlabel, or a textfield. But, it has to be displayed real-time (as I'm typing the values).
Well, you would want to update "after" the user has finished editing a cell and saves the value to the table.
So you can use a TableModelListener. You add the TableModelListener to the TableModel. Then when the data is saved an event will be generated and you can recalculate the values and update the label.
Check out the following for a simple example to get your started: TableModelListener and multiple column validation. Your logic in the listener will change based on your exact requirement.
You can do this by attaching a defaultTableModel to your JTable. After attaching TableModel to your JTable. You can use command JTable.addRow(Object[]) to add rows to table.

How can i save the data in sql from the cell after editing in jTable(autosave)?

i have populated Jtable, but now i want to update sql record if i change a cell's value then it should change in sql databases automatically.
i want to update sql record if i change a cell's value then it should change in sql databases automatically
There is no such thing as autosave (in the base JDK classes). So you will need to write code to listen for changes to the data in the table and then update your database manully using SQL.
For this you can add a TableModelListener to the TableModel of your JTable. Then when the event fires you get the data from the TableModel and update your database.
Note the TableModelListener will generate an event if you start to edit the cell and just tab out of the cell even if you don't change the data. So you may want to consider using the Table Cell Listener which will only generate an event if the data in the cell is actually changed.

Related to checkbox in jtable

I am using a table to display data.
I am providing checkbox to each row of a table to perform some operations based on selection. When I did like that, I am able to check multiple rows.
But my requirement is, at any point of time I should check only one checkbox. To be precise, I need the behavior of Buttongroup to all checkboxes in table.
How can I do this?
If you really want to use checkboxes, I assume your TableModel holds a boolean for those checkboxes. It should be trivial to move the logic for the single selection to the TableModel.
If you do not need the checkboxes but just want to operate on the selected rows (see JTable#getSelectedRows), you can adjust the ListSelectionModel which is present on the JTable to only allow for single selection (see ListSelectionModel#SINGLE_SELECTION)
CheckOne is a complete example that simply clears all check boxes in a specific column and sets the new value. This related example uses JRadioButton.

Creating front-end user interactive table using MySQL as back-end

Creating front-end (Java) user interactive table using MySQL as back-end
Now im trying to create user interactive form.
Untill now, I have created a form view, using swing components, JLable, JTextfield where user enters data. JButtons, 'new' 'save' 'delete' 'edit', which listens user action through ActionListner.
A table that 'extends' AbstractTableModel. Table values are the ResultSet values. i have used MySQL connectivity.
Table is displayed. User can now add new row to it, using 'New' and 'Save' button.
My problem is, i need the corresponding TextFields to display the corresponding row user selects in the displayed table, so that 'edit' and 'delete' would be user interactive. users are allowed to select table's row. Need Help.
Im sorry if any mistake in my question format and language. Thank you!
i need code for creating table ...
ple help me on tis....
i need code for creating table
How much will you pay? :)
..i need the corresponding TextFields to display the corresponding row user selects in the displayed table..
For that you can use,
Give a button, like EDIT and in the event handler for EDIT use something like,
jTextField.setText( jTable.getValueAt(
jTable.getSelectedRow(),
jTable.getSelectedColumn())
.toString()
);
2.As an alternative you can also utilize the event in jtable like mouseClicked with the above code
Now regarding the edit and delete , you may utilize the focusLost event of the textfield or use a EDIT or DELETE button, and carryout the updation, which will be much reasonable option.
Additionaly have a look at this : Using JDBC with GUI API

Categories

Resources