Active Patients Who Have Turned 18 During Treatment

SELECT 
COALESCE(b.provcode,'None') AS "Primary Prov",
a.lastname, 
a.firstname, 
a.ID, 
DATEDIFF(year,DOB,intakedate) AS "Age At Intake", 
DATEDIFF(year,DOB,current date) AS "Age Now" 
FROM 
patients a
JOIN providers b ON a.providernum = b.providernum
WHERE 
flag = 0   //active patient 
AND dischargedate IS NULL   //no discharge date has been entered 
AND "Age At Intake" < 18     
AND "Age Now" >= 18
ORDER BY "Primary Prov", a.lastname, a.firstname, a.id