mongodb group by first character

Question

I have a problem in mongodb. I want to create aggregation witch result will be like this: ``` A 10 B 2 C 4 D 9 E 3 ... ``` I have a column `words` in my table and I want to group my records according to first character of column `words`. I find resolve for `sql` but not for mongo. I will be very grateful for your help

Accepted Answer

You don't show what the docs in your collection look like, but you can use the `aggregate` collection method to do this:

```
// Group by the first letter of the 'words' field of each doc in the 'test'
// collection while generating a count of the docs in each group.
db.test.aggregate({$group: {_id: {$substr: ['$words', 0, 1]}, count: {$sum: 1}}})
```

mongodb group by first character

Solution

Problem