Self joining columns from the same table with calculation on one column not displaying column name

I am fairly new to SQL and having issues figuring out how to solve the simple issue below. I have a dataset I am trying to self-join, I am using (b.calendar_year_number -1) as one of the columns to join. I applied a calculation of -1 with the goal of trying to match values from the previous year. However, it is not working as the resulting column shows (No column name) with a screenshot attached below. How do I change the alias to b.calendar_year_number after the calculation?

Code:

SELECT a.day_within_fiscal_period,
       a.calendar_month_name,
       a.cost_period_rolling_three_month_start_date,
       a.calendar_year_number,
       b.day_within_fiscal_period,
       b.calendar_month_name,
       b.cost_period_rolling_three_month_start_date,
       (b.calendar_year_number -1) 
FROM [data_mart].[v_dim_date_consumer_complaints] AS a
JOIN [data_mart].[v_dim_date_consumer_complaints] AS b 
  ON b.day_within_fiscal_period = a.day_within_fiscal_period AND
  b.calendar_month_name = a.calendar_month_name AND
  b.calendar_year_number = a.calendar_year_number

Answer

I am using (b.calendar_year_number -1) as one of the columns to join.

Nope, you’re not. Look at your join statement and you’ll see the third condition is:

b.calendar_year_number = a.calendar_year_number

So just change that to include the calculation. As far as the ‘no column name’ issue, you can use colname = somelogic syntax or somelogic as colname. Below, I used the former syntax.

select      a.day_within_fiscal_period,
            a.calendar_month_name,
            a.cost_period_rolling_three_month_start_date,
            a.calendar_year_number,
            b.day_within_fiscal_period,
            b.calendar_month_name,
            b.cost_period_rolling_three_month_start_date,
            bCalYearNum = b.calendar_year_number 
from        [data_mart].[v_dim_date_consumer_complaints] a
left join   [data_mart].[v_dim_date_consumer_complaints] b 
                on b.day_within_fiscal_period = a.day_within_fiscal_period 
                and b.calendar_month_name = a.calendar_month_name 
                and b.calendar_year_number - 1 = a.calendar_year_number;