SQL：SQL查询中的Union All时出错

Question

Below is my query. I am using UNION ALL because i need to bring data when MONTH column is both NOT NULL and NULL. But this is not working, i am wondering why.

    SELECT metricname,
         careertrackid,
         monthyrname,
         SUM(metricvalue) AS metricval,
         CASE
           WHEN MONTH IS NOT NULL THEN CONVERT(VARCHAR,YEAR) + LPAD(CONVERT(VARCHAR,MONTH),2,'0')
           ELSE CONVERT(VARCHAR,acnfiscalyear) + CONVERT(VARCHAR,acnfiscalquarter)
         END AS dispmonth
  FROM atp_9375_forecast,
       vspforecasts
  WHERE ibfcollectionid = vspforecasts.ibfid
  AND   (YEAR>= 2018 AND MONTH>= 7)
  GROUP BY careertrackid,
           metricname,
           dispmonth,
           monthyrname
  ORDER BY dispmonth

UNION ALL

SELECT metricname,
         careertrackid,
         monthyrname,
         SUM(metricvalue) AS metricval,
         CASE
           WHEN MONTH IS NOT NULL THEN CONVERT(VARCHAR,YEAR) + LPAD(CONVERT(VARCHAR,MONTH),2,'0')
           ELSE CONVERT(VARCHAR,acnfiscalyear) + CONVERT(VARCHAR,acnfiscalquarter)
         END AS dispmonth
  FROM atp_9375_forecast,
       vspforecasts
  WHERE ibfcollectionid = vspforecasts.ibfid
  AND   (YEAR>= 2018 AND MONTH IS NULL)
  GROUP BY careertrackid,
           metricname,
           dispmonth,
           monthyrname
  ORDER BY dispmonth

Is there any other way in which i can still apply MONTH filter but that should include both NULL and NOT NULL as MONTH column is having both these values in table.

Sample Result This is the desired result but this only comes when MONTH column includes NULL and NOT NULL

{"201806":"0.00","201807":"0.00","201808":"0.00","201809":"0.00","201810":"0.00","201811":"0.00","FY19Q2":"0.00","FY19Q3":"0.00","FY19Q4":"0.00","FY20Q1":"0.00"}

Answer 1

From your question your union all two queries are almost the same, only in the month to judge, you don't need to use UNION ALL just use add a condition (MONTH>= 7 OR MONTH IS NULL) in WHERE

SELECT metricname,
     careertrackid,
     monthyrname,
     SUM(metricvalue) AS metricval,
     CASE
       WHEN MONTH IS NOT NULL THEN CONVERT(VARCHAR,YEAR) + LPAD(CONVERT(VARCHAR,MONTH),2,'0')
       ELSE CONVERT(VARCHAR,acnfiscalyear) + CONVERT(VARCHAR,acnfiscalquarter)
     END AS dispmonth
FROM atp_9375_forecast INNER JOIN 
   vspforecasts ON ibfcollectionid = vspforecasts.ibfid
WHERE (YEAR>= 2018 AND (MONTH>= 7 OR MONTH IS NULL))
GROUP BY careertrackid,
       metricname,
       dispmonth,
       monthyrname
ORDER BY dispmonth

Note

I suggest avoid to use , comma to connect tables, because it's an old style, you can use join instead of it.