how to add hidden column in slickgrid

There is no implied relationship between the data and the columns in the grid - the two exist completely independent of each other. So your data can contain many more fields than are actually bound to grid columns.

Example:

var grid;
var columns = [
  {id: "title", name: "Title", field: "title"},
  {id: "duration", name: "Duration", field: "duration"},
  {id: "%", name: "% Complete", field: "percentComplete"},
  {id: "effort-driven", name: "Effort Driven", field: "effortDriven"}
];

var options = {
  enableCellNavigation: true,
  enableColumnReorder: false
};

$(function () {
  var data = [];
  for (var i = 0; i < 500; i++) {
    data[i] = {
      title: "Task " + i,
      duration: "5 days",
      percentComplete: Math.round(Math.random() * 100),
      start: "01/01/2009",
      finish: "01/05/2009",
      effortDriven: (i % 5 == 0)
    };
  }

  grid = new Slick.Grid("#myGrid", data, columns, options);
})

Here my dataarray contains fields start and finish but I have chosen to exclude them when creating my columns array.

I think you can achieve this by using grid.setColumns - lets say you had columns={id, a, b, c} set while declaring the grid; after the grid is initialized, you can call the grid.setColumns(newColumns) - where newColumns is the new column array which excludes id - newColumns={a, b, c}.

This column is still accessible and all data associated with it should be available as well.

Hope this helps!