Server-side JavaScript - how lookup rows in data extension in Marketing cloud

Question

I just started using SSJS and the syntax is a bit new.

I need to check if a subsriber exists in a data extension, based on email address.

if (IsEmailAddress(submitterEmail)){
var requestsDE = DataExtension.Init('dataextensionname');
var exists = requestsDE.Rows.Lookup(["email"], [submitterEmail]);
var rows = rowCount(exists);
if rows < 1 {
alert('less than one row')
}
else do stuff

So I want to check if the email address 'submitterEmail' at all exists in the data extension (column 'email'), and then I want to count if there are any rows. If there is I eventlually want to update the row, else I want to add a row.

Anyone who please can give me a hint or a code snippet on how to do this? (my code doesn't work and I think there is something wrong in the countRow or Lookup area)

Answer 1

The rowCount() is not a SSJS function in SFMC.

Here's a store lookup example. It should give you a good place to start:

<script type="javascript" runat="server">

Platform.Load("core","1.1.1");

try {

    var postalCode = Attribute.GetValue("Zip");
    var storePostalCodeDe = DataExtension.Init("StorePostalCodes");
    var storePostalCode = storePostalCodeDe.Rows.Lookup(["PostalCode"],[postalCode]);
    Variable.SetValue("foundStore", storePostalCode.length > 0);

    if (storePostalCode.length > 0) {
            var storeDe = DataExtension.Init("Stores");
            var stores = storeDe.Rows.Lookup(["StoreID"],[storePostalCode[0].StoreID]);
            var store = stores[0];
            var storeAddress = store.Storename + " " + store.Address1 + " " +"<br>" + store.City + ", " + store.Province + " " + store.PostalCode + ", " + store.Phone
            Variable.SetValue("storeAddress", storeAddress)
    }

} catch (e) {
  Write("<br>Exception: " + e);
}

</script>
<br>foundStore: %%=v(@foundStore)=%%
<br>storeAddress: %%=v(@storeAddress)=%%

Reference

Core Library Server-Side JavaScript Functions