1
00:00:02,110 --> 00:00:05,700
So how can we ensure that email is unique?

2
00:00:05,710 --> 00:00:09,440
So first of all, I'll delete that redundant entry here,

3
00:00:09,550 --> 00:00:17,080
so in my users collection I'll delete one entry and I'll identify the entry by ID by using that objectid

4
00:00:17,100 --> 00:00:19,000
here

5
00:00:19,300 --> 00:00:27,970
and now we can add a unique index. So on users, we can create that index on the email field, we pass some

6
00:00:27,970 --> 00:00:31,040
configuration here where we set unique to true

7
00:00:31,210 --> 00:00:36,030
and now we'll get an error if we try to insert something which exists already.

8
00:00:36,050 --> 00:00:38,670
So now I inserted that index

9
00:00:38,740 --> 00:00:43,230
and now let's try inserting that same email one more time.

10
00:00:46,300 --> 00:00:48,400
Now you see I get an error here

11
00:00:49,500 --> 00:00:56,740
and indeed, I print the error here on the backend server, duplicate key error collection.

12
00:00:57,050 --> 00:00:58,750
So now I get this error

13
00:00:58,790 --> 00:01:03,820
and of course you can handle it in a different way if you want but now we make sure that node duplicate

14
00:01:03,860 --> 00:01:10,730
data for the e-mail can end up. So that is another useful thing which we simply added by adding an index.