Please give me a solution

[neemapremano]

I have a table called patient.i am using count of test_code.every patient can have more than one test_code.and each test_code can be performed more than one time.I want to get the patients who have only count as 1 and doesnot have count more than 1

patient COunt(for each test_code)
PAT001 1
1
2
3
PAT002 1
1
PAT003 5
3
PAT004 1
1
1

when i am using the following query i nam getting patients who have both count=1 and count greater than.

SELECT A.PATIENT_ID,A.SPECIMEN_NO,COUNT(A.GROUP_TEST_CODE ) AS "COUNT" FROM RL_RESULT_TEXT A
GROUP BY A.PATIENT_ID,A.SPECIMEN_NO
HAVING PATIENT_ID LIKE 'QH%' AND COUNT(A.GROUP_TEST_CODE)=1



Please help me out....