Я вообще хз, у самого такая задача
var table = document.querySelector('table[id=dataTable] tbody')
function getTr(event) {
let tr = event.target.closest('tr')
if (!tr) return;
if (!table.contains(tr)) return;
return tr;
}
table.onselectstart = function (event) {
return false;
}
table.onmousedown = function (event) {
table.mousedown = true
highlight(getTr(event))
}
table.onmouseup = function (event) {
table.mousedown = false
}
table.onmouseover = function (event) {
if (table.mousedown) {
highlight(getTr(event))
}
}
function highlight(element) {
element.classList.toggle('bg-dark')
}
как-то так