probelm of having clause

Question

hi ,

 

i have one problem with this query please help me. if  iam using having cluase iam not getting records . if  iam run from select to group by iam getting results . please help me how to use this query with having clause

 

SELECT
CONCAT(s.Skill,'(',es.Experience,' Months',')')AS Skills
FROM projectemployee p
LEFT OUTER JOIN employeeskills es ON p.EmployeeId =es.EmployeeId
LEFT OUTER JOIN skilllookup s ON es.Skill =s.SkillId
WHERE CURDATE() BETWEEN p.StartDate AND p.EndDate
GROUP BY p.EmployeeId
HAVING SUM(p.AllocationPercentage) < 100;