How to choose the average price from MySQL table, but to and item id?

There is a table that looks like this:

+-------------+---------+
| product_id | price |
+-------------+---------+
| 0001 | 150 |
| 0001 | 155 |
| 0001 | 148 |
| 0004 | 162 |
+-------------+---------+

I need to get the response like this:

+-------------+---------+
| product_id | price |
+-------------+---------+
| 0001 | 153,75 |
+-------------+---------+

ie in the line item id and its average price. Write the query:

SELECT 
ROUND(AVG( `price`)) AS 'middle_price', 
'product_id '

FROM `products_prices` 
WHERE 
`region_id`= 77 AND //Region of the buyer, different region, different shops
`product_id ` IN (1,2,3) 
GROUP BY `product_id `


Get in the answer column and product_id middle_price , only in the string instead of the value of an item ID, product_id written. Where I went wrong? Did not realize at the end of the 11 hour working day ))
June 3rd 19 at 19:27
3 answers
June 3rd 19 at 19:29
'product_id' string
`product_id` column name
Feel the difference
June 3rd 19 at 19:31
No way.
June 3rd 19 at 19:33
Select min(Id), avg(price) from ... Group by id

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