Create another column based on the conditions in SQL

Question

I need help to create a query for this output below. As you can see in the below dataset, I wanted to have the patient record in a single row with all the details

For example, Shahin Adam need to have only 1 single record combine the details of Dose Number 1 and Dose Number 2 with the date of each dose

DESIRED OUTPUT

Thank you for your help

Answer 1

I think you just want conditional aggregation:

select lastname, firstname,
       max(case when dosenumber = 1 then dosenumber end) as dosenumber_1,
       max(case when dosenumber = 1 then timeofevent end) as timeofevent_1,
       max(case when dosenumber = 2 then dosenumber end) as dosenumber_2,
       max(case when dosenumber = 2 then timeofevent end) as timeofevent_2
from t
group by lastname, firstname;

Answer 2

As per desired output result section show only 2 records whose first name starts with A. That's why where clause is enabled here. If all patients info need then disable where clause.

SELECT PatientLastName, PatientFirstName
     , MAX(CASE WHEN DoseNumber = 1 THEN DoseNumber ELSE NULL END) DoseNumber1
     , MAX(CASE WHEN DoseNumber = 1 THEN TimeOfEvent ELSE NULL END) TimeOfEvent1
     , MAX(CASE WHEN DoseNumber = 2 THEN DoseNumber ELSE NULL END) DoseNumber2
     , MAX(CASE WHEN DoseNumber = 2 THEN TimeOfEvent ELSE NULL END) TimeOfEvent2
FROM table_name
WHERE PatientFirstName like 'A%'
GROUP BY PatientLastName, PatientFirstName
ORDER BY PatientFirstName;