Non-grouping field error with ONLY_FULL_GROUP_BY mode and tables that have the same column name
It seems a bug (MySQL 5.5 and 5.6). A temporary solution that can be useful is:

SELECT `t1`.`c1`, `der`.`_c1`
FROM `t1`, (SELECT `c1` `_c1`, `c2` `_c2`
            FROM `t2`) `der`
GROUP BY `t1`.`c1`, `der`.`_c1`
HAVING `t1`.`c1` &gt; 1 AND `der`.`_c1` &gt; 1;


SQL Fiddle demo

In MySQL 5.7.11, the query:

SELECT `t1`.`c1`, `t2`.`c1`
FROM `t1`, `t2`
GROUP BY `t1`.`c1`, `t2`.`c1`
HAVING `t1`.`c1` &gt; 1 AND `t2`.`c1` &gt; 1;


runs smoothly.