Du kan JOIN
din forespørgsel tilbage mod hovedtabellen som en underforespørgsel, for at få de originale rækker og filnavne:
SELECT
main.number,
main.file
FROM
table AS main
/* Joined against your query as a derived table */
INNER JOIN (
SELECT number, COUNT(*) AS sum domains
FROM table
WHERE RIGHT(file, 2) = '_1'
GROUP BY number
HAVING sum domains > 1
/* Matching `number` against the main table, and limiting to rows with _1 */
) as subq ON main.number = subq.number AND RIGHT(main.file, 2) = '_1'
http://sqlfiddle.com/#!2/cb05b/6
Bemærk, at jeg har erstattet din LIKE '%_1'
med RIGHT(file, 2) = '_1'
. Det er dog svært at sige, hvilken der vil være hurtigere uden et benchmark.