MYSQL: sub-query help in WHERE clause

Question

I'm trying to build an SQL query but I'm receiving the following error:

#1054 - Unknown column 'r.id' in 'where clause' 

This is my query:

SELECT *, COUNT(id) AS result_count 
    FROM rate_clicks AS rc 
    WHERE click_type = 'details' 
    AND created_at > 1463517035 
    AND rate <= (SELECT rate 
        FROM rates AS r 
        WHERE r.id = rc.rate_id) 
    GROUP BY rate_id 
    ORDER BY result_count DESC LIMIT 5

I haven't used sub-queries before, so I assume this is where I'm failing. Your help is greatly appreciated!

Answer 1

MySQL doesn't accepted alias to parent in subquery. You should join instead:

SELECT *, COUNT(id) AS `result_count` 
FROM `rate_clicks` AS `rc` 
WHERE `click_type` = 'details' AND `created_at` > 1463517035 
AND `rate` <= (SELECT `rate` FROM `rates` AS `r` 
               inner join `rate_clicks` as rc1  `r.id`=`rc1.rate_id`) 
GROUP BY `rate_id` 
ORDER BY `result_count` DESC LIMIT 5

Answer 2

i post it as answer. You have use wrong backticks

change this:

WHERE `r.id`=`rc.rate_id`

to

WHERE `r`.`id`=`rc`.`rate_id`

sample

MariaDB [bb]> SELECT * FROM useindex i WHERE `i.num1`= 999 LIMIT 10;
ERROR 1054 (42S22): Unknown column 'i.num1' in 'where clause'
MariaDB [bb]>
MariaDB [bb]> SELECT * FROM useindex i WHERE `i`.`num1`= 999 LIMIT 10;
+-------+------+------+
| id    | num1 | num2 |
+-------+------+------+
|   511 |  999 |  686 |
|  1878 |  999 |  687 |
|  3241 |  999 |  686 |
|  3245 |  999 |  688 |
|  4608 |  999 |  687 |
|  5971 |  999 |  685 |
|  5975 |  999 |  687 |
|  7338 |  999 |  686 |
|  8705 |  999 |  687 |
| 10068 |  999 |  686 |
+-------+------+------+
10 rows in set (0.00 sec)

MariaDB [bb]>