having

select f.folderno
from lims_folders f
where exists (select 1
from lims_folderservgrp fs
where fs.foldersid = f.foldersid
HAVING count(1) > 1)

查询出重复数据

SELECT t.`TESTNAME`,COUNT(1)FROM lims_tests t GROUP BY t.`TESTNAME` HAVING COUNT(1) > 1