JDataGrid Database Component FAQ

JDataGrid Database Component Frequently Asked Questions

There is no Save option on this demo. How do clients handle a SAVE to update their database.

The demo will save the changes to database as needed, you can set the save behavior via the following methods:

   ResultSetTableModel.setAutoInsertPolicy(int);
   ResultSetTableModel.setAutoUpdatePolicy(int);

You can also save the changes by invoke the following method:

   ResultSetTableModel.acceptChanges();

How do I commit changes made by the user in the table to the database?: You can invoke the methods "acceptChanges" in ResultSetTableModel or RowSetTableModel.

Is there an easy way to link an "end of page" in the table to fetching the next chunk of the ResultSet?: JDataGrid Database Edition 2.5.0 and later support the feature "lazy fetch the record set".

How to use the license code?: You can input it on the "About" dialog.
You can also use the following code to register the license code in
your programming code:

// the code means the above license data
LicenseManager.getInstance().addLicenseData(code);

How to switch off cell selection border?: Use the following method in JDataGrid:
dataGrid.setSelectionBorderPainted(false);

How to enable the column sorting in JDataGrid?: You should enable the following client property in JDataGrid:
     dataGrid.setModel(new DefaultColumnSorter(createModel()));
     dataGrid.putClientProperty("JDataGrid.columnSortingEnabled", Boolean.TRUE);
     dataGrid.putClientProperty("JDataGrid.switchUnsortedOrderEnabled", Boolean.TRUE);
     And you should use the default JTableHeader build-in JDataGrid.

Whey the there is nothing (button or icon) which is displayed in the JTableHeader to allow sorting action?: You should use the default JTableHeader build-in JDataGrid, Because the default JTableHeader cannot provide the support for column sorting, it have not this feature, such as show a arrow icon, or act as a button pushing.

How to enable the color effect for print preview?: JPrintPreview provides the following methods to enable color print preview:
JPrintPreview.setColorType(JPrintPreview.COLOR);

Why encounter an error when add "TableColumn" in JDataGrid?: Please use DefaultDataGridModel.addColumn(null) to add new column in JDataGrid.

How to set a Renderer for AComboBox that aligns the text on the left?: You can use the "ObjectCellRenderer" in com.zfqjava.swing.cell directly, it has method
"setDefaultHorizontalAlignment" and "setDefaultVerticalAlignment".

How do I set the format of the renderer to format the date in short form: MM/DD/YYYY?: You can create "DateCellRenderer" instance, it's ObjectCellRenderer subclass, and pass a new SimpleDateFormat("MM/dd/yyyy");

How to set a columnHeader for each column and to allow column resizing automatically?: The method "JDataGrid.sizeColumnWidthToFit" can size the column to fit it's contents.

How to write a grid that is sortable and has even rows one color and odd rows another color?: The JDataGrid has provide this feature since version 1.8, you can invoke the following code:

dataGrid.setAlternatingRowBackground(Color.gray);
dataGrid.setAlternatingRowForeground(Color.white);

Is there any way to add in a checkbox component/renderer for a table column header?: The following code enable the checkbox in JDataGrid table header:

     JDataGrid dataGrid = getDataGrid();
     BooleanCellRenderer renderer = new BooleanCellRenderer();
     renderer.setComponentType(BooleanCellRenderer.CHECK_BOX);
     // gloablly enable the check box renderer
     // dataGrid.getTableHeader().setDefaultRenderer(renderer);
     dataGrid.getColumnModel().getColumn(0).setHeaderRenderer(renderer);

Is it possible to prevent a single column from being moved? I have a list of columns that the user can move, but I want the first column to stay the first column (not freezing a column or window)?: This function can be implemented by write a customize TableColumnModel, override the method:

           TableColumn firstColumn = new TableColumn(0);
           // override the method in TableColumnModel
           public TableColumn getColumn(int columnIndex) {
                if(columnIndex == 0) {
                      return firstColumn;
                } else {
                       return super.getColumn(columnIndex);
                 }
           }

How to sets column width of JDataGrid?

The JDataGrid provides this feature directly since 1.2, try the following code to set JDataGrid column width:

  JDataGrid dataGrid = createDataGrid();
  // set the default column width
  dataGrid.setColumnWidth(100);
  // set the column width at the specified column
  dataGrid.setColumnWidth(2, 200);

Why must invoke reload method in ResultSetTableModel?: The ResultTableTableModel is loading data in background thread, invoke reload method will start the background thread and then loading data from data source, the will give a chance for set it to JDataGrid.

How to set color of the even and odd row?

Overide the JDataGrid and add the following code:

public Component prepareRenderer(TableCellRenderer renderer, int row, 
int column) {
    Component c = super.prepareRenderer(renderer, row, column);
    if(row % 2 == 0) {
        // even row
	c.setBackground(Color.gray);
    } else {
        // odd row
	c.setBackground(Color.white);
    }
    return c;
}

How to set the background area around JDataGrid?

Should sets the background of the JDataGrid viewport, try the following code:

dataGrid.getParent().setBackground(Color.white);

You should set the background and it's viewport background of the row header
or column header both, try the following code:

  JDataGrid dataGrid = createDataGrid();
  JScrollPane scrollPane = new JScrollPane(dataGrid);
  // ensure the row header and column header have add into JScrollPane
  scrollPane.setRowHeaderView(dataGrid.getRowHeader());
  scrollPane.setColumnHeaderView(dataGrid.getTableHeader());
  // set the background of the datagrid
  dataGrid.getRowHeader().setBackground(Color.white);
  dataGrid.getRowHeader().getParent().setBackground(Color.white);
  dataGrid.getTableHeader().setBackground(Color.white);
  dataGrid.getTableHeader().getParent().setBackground(Color.white);