Using first value in select option to filter column

ljones

I've managed to set up a select filter for one of the columns on a datatable I have, but it only filters when an option is selected manually. I'd like it to filter to the first value in the list when the page loads and then for it to change when the next value is selected (I don't want to be able to have rows showing that have different values in this particular column, the user should have to choose a different option from the select function to change the dataset.).