get a count of records matching a value

getalex

I have a table that should have a unique column value for each row. I want to prevent new data entry if a row exists with this unique key value already.. my thought was i could validate on submit, something like this:

// second column should be unique
var total = dt.columns(1).search( newRowKeyToFind ).count();
if (total > 0) return false or alert of issue ...

I read the API says search won't actually execute until the draw() method is called, so I tried using the Filter API, but can't get the value to match or find any examples on usage for the scenario I illustrated above.

Can somebody please help with some simple code for this?

getalex

This is the best I could come up with, please let me know if there's a better way:

var valueToFind = "peanuts";

var duplicateCheck = dt.columns(1).data().filter(function (value, index) {
        var foundDuplicate = false;
        for (i = 0; i < value.length; i++) {
            if (value[i] === valueToFind) {
                foundDuplicate = true;
                break;
            }
        }
        return foundDuplicate;
    }).count();

kthorngren

Maybe something like this?

var valueToFind = "peanuts";
 
var duplicateCheck = dt.columns(1).data().filter(function (value, index) {
        return value ===  valueToFind ? true : false;
    }).length;

duplicateCheck should equal 0 if peanuts is not in the data or will equal the number of found results. This is based on the example code in the filter() docs.

Kevin