Reputation: 619
I m working on weird SQL query
Patient_ID Count order_no
1 1 1
2 1 2
2 0 3
2 0 4
3 1 5
3 0 6
where I need to count the patient as above, for every new patient , the count column is 1. If repeated , the below entry it should be 0
I m confused how should make that work in SQL
Upvotes: 0
Views: 155
Reputation: 22994
In order to make the first entry 1 and all subsuqent entries 0, I believe you need a ranking with partition by the order number. Please checkout the sqlfiddle below to test results.
http://www.sqlfiddle.com/#!3/4e2e2/17/0
SELECT
patient_id
,CASE WHEN r.rank = 1
THEN 1
ELSE 0
END
, order_number
FROM
(
SELECT
order_number
,patient_id
,ROW_NUMBER() OVER (PARTITION BY patient_id ORDER BY order_number)[rank]
FROM
PatientTable
)r
Upvotes: 7