Or can be used with Where to filter records.

Sql

Select * From Table_Name;
Where
Column1=some_value
or
Column2=some_another_value;

JsStore

connection.select({
    from: "Table_Name",
    where: {
        Column1: some_value,
        or: {
            Column2: some_another_value
        }
    }
}).then(function(results) {
    //results will be array of objects.
    console.log(results);
}).catch(function(error) {
    alert(error.message);
});;

Example