Question

以下是我的查询。我正在使用UNION ALL，因为当MONTH列既不是NULL又是NULL时，我需要带数据。但这不起作用，我想知道为什么。

    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

还有没有其他方法可以应用MONTH过滤器，但是应该同时包含NULL和NOT NULL，因为MONTH列在表中同时具有这两个值。

采样结果 这是理想的结果，但这仅在MONTH列包含NULL和NOT NULL时出现

{"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

根据您的问题，您的union all两个查询几乎相同，仅需month来判断，您无需使用UNION ALL，只需使用添加条件{{1 }}在(MONTH>= 7 OR MONTH IS NULL)

中

WHERE

注意

我建议避免使用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逗号连接表，因为它是一种旧样式，可以使用,代替它。

SQL：SQL查询中的Union All时出错

1 个答案: