Automatically generate a unique sequential ID in Google Sheets - google-apps-script

Question

In Google Sheets, I have a spreadsheet called Events/Incidents which staff from various branches populate. I want Column B to automatically generate a unique ID based on the year in column A and the previously populated event. Given that there could be several events on a particular day, rows in column A could have duplicate dates.
The following is an example of what I am looking for in column B:
There can be no duplicates. Would really appreciate some help with either code or formula.

Answer 1

There are my thoughts https://github.com/contributorpw/google-apps-script-snippets/blob/master/snippets/spreadsheet_autoid/autoid.js
The main function gets a sheet and makes the magic
/**
*
* #param {GoogleAppsScript.Spreadsheet.Sheet} sheet
*/
function autoid_(sheet) {
var data = sheet.getDataRange().getValues();
if (data.length < 2) return;
var indexId = data[0].indexOf('ID');
var indexDate = data[0].indexOf('DATE');
if (indexId < 0 || indexDate < 0) return;
var id = data.reduce(
function(p, row) {
var year =
row[indexDate] && row[indexDate].getTime
? row[indexDate].getFullYear() % 100
: '-';
if (!Object.prototype.hasOwnProperty.call(p.indexByGroup, year)) {
p.indexByGroup[year] = [];
}
var match = ('' + row[indexId]).match(/(\d+)-(\d+)/);
var idVal = row[indexId];
if (match && match.length > 1) {
idVal = match[2];
p.indexByGroup[year].push(+idVal);
}
p.ids.push(idVal);
p.years.push(year);
return p;
},
{ indexByGroup: {}, ids: [], years: [] }
);
// Logger.log(JSON.stringify(id, null, ' '));
var newId = data
.map(function(row, i) {
if (row[indexId] !== '') return [row[indexId]];
if (isNumeric(id.years[i])) {
var lastId = Math.max.apply(
null,
id.indexByGroup[id.years[i]].filter(function(e) {
return isNumeric(e);
})
);
lastId = lastId === -Infinity ? 1 : lastId + 1;
id.indexByGroup[id.years[i]].push(lastId);
return [
Utilities.formatString(
'%s-%s',
id.years[i],
('000000000' + lastId).slice(-3)
)
];
}
return [''];
})
.slice(1);
sheet.getRange(2, indexId + 1, newId.length).setValues(newId);
}
I think it can be simplified in the feature.

Answer 2

There is an easier way to generate unique values that works for me, pick a #, then do +1. Ctrl C, then Ctrl shift V to paste back and remove the formula. Now you are left with thousands of unique IDs.
This is a manual solution but you can do an entire database in a matter of seconds every once in a while.