Using DateAdd function to Calculate between 2 Dates in SQL

Question

I am trying to find out and flag if patient had an x-ray within one day when they first showed up in ER.

SELECT perosonID,
       xray_code,
       xray_date,
       admit_date,
       CASE
         WHEN xray_code IN ( '212', '345', '489' )
              AND admit_date BETWEEN DateAdd(day, 0, xray_date) 
                                 AND DateAdd(day, 1, xray_date) THEN 1
         ELSE 0
       END AS flag
FROM   my table 

my results seem to be wrong and I am not sure what I am doing wrong here. thanks

Answer 1

Select perosonID
     , xray_code
     , xray_date
     , admit_date
     , Case when xray_code in (‘212’, 345’, ‘489’) 
             and  DATEDIFF(DAY, admit_date, xray_date) <= 1 
             then 1 
        else 0 end as flag
from my table