Question

From MySQL – Get row number on select
I know how to get the row number / rank using this mysql query:

SELECT @rn:=@rn+1 AS rank, itemID
FROM (
  SELECT itemID
  FROM orders
  ORDER BY somecriteria DESC
) t1, (SELECT @rn:=0) t2;

The result returns something like this:

+--------+------+
| rank | itemID |
+--------+------+
|  1   |   265  |
|  2   |   135  |
|  3   |   36   |
|  4   |   145  |
|  5   |   123  |
|  6   |   342  |
|  7   |   111  |
+--------+------+

My question is: How can I get the result in 1 simple SINGLE QUERY that returns items having lower rank than itemID of 145, i.e.:

+--------+------+
| rank | itemID |
+--------+------+ 
|  5   |   123  |
|  6   |   345  |
|  7   |   111  |
+--------+------+

Oracle sql query is also welcomed. Thanks.

Answer 1

An Oracle solution (not sure if it meets your criteria of “one simple single query”):

WITH t AS
(SELECT item_id, row_number() OVER (ORDER BY some_criteria DESC) rn
   FROM orders)
SELECT t2.rn, t2.item_id
  FROM t t1 JOIN t t2 ON (t2.rn > t1.rn)
 WHERE t1.item_id = 145;

My assumption is no repeating values of item_id.

Attempting to put this in MySQL terms, perhaps something like this might work:

SELECT t2.rank, t2.itemID
  FROM (SELECT @rn:=@rn+1 AS rank, itemID
          FROM (SELECT itemID
                  FROM orders
                 ORDER BY somecriteria DESC), (SELECT @rn:=0)) t1 INNER JOIN
       (SELECT @rn:=@rn+1 AS rank, itemID
          FROM (SELECT itemID
                  FROM orders
                 ORDER BY somecriteria DESC), (SELECT @rn:=0)) t2 ON t2.rank > t1.rank
 WHERE t1.itemID = 145;

Disclaimer: I don’t work with MySQL much, and it’s untested. The Oracle piece works.