SQL - 2个表值按第三个未连接值分组

Question

我想创建一个图表，用于从SQL数据库中生成的2个用户问题中提取数据。

问题是用户问题与答案一样存储在同一个表中。唯一的连接是问题字符串包含年份值，我使用命令提取的年份值，以便输出一个名为'YEAR'的列，列中包含从2013年到2038年（25年期间）的整数值列表， 。 然后，我想从每个'YEAR'拉相应的答案（'预测'和'实际'），以便我可以绘制一个图表与每年的几个值（抱歉，如果这没有任何意义）。图表应显示25年期间的预测线，第二行（或列）显示多年来人口填充时的实际值。然后我就能够想象，如果我们的实际值是接近我们原来的预测数字（长期目标！）

下面的代码

SELECT CAST((LEFT(F_TASK_ANS.TA_ANS_QUESTION,4)) AS INTEGER) AS YEAR, 
-- first select takes left 4 characters of question and outputs value as string then coverts value to whole number. 
CAST((CASE WHEN F_TASK_ANS.TA_ANS_QUESTION LIKE '%forecast' THEN F_TASK_ANS.TA_ANS_ANSWER END) AS NUMERIC(9,2)) AS 'FORECAST', 
CAST((CASE WHEN F_TASK_ANS.TA_ANS_QUESTION LIKE '%actual' THEN ISNULL(F_TASK_ANS.TA_ANS_ANSWER,0) END) AS NUMERIC(9,2)) AS 'ACTUAL' 
-- actual value will be null until filled in each year therefore ISNULL added to replace null with 0.00. 
FROM F_TASK_ANS INNER JOIN F_TASKS ON F_TASK_ANS.TA_ANS_FKEY_TA_SEQ = F_TASKS.TA_SEQ 
WHERE TA_ANS_ANSWER <> '' 
AND (TA_TASK_ID LIKE '%6051' OR TA_TASK_ID LIKE '%6052') 
-- The two numbers above refer to separate PPM questions that the user enters a value into 

我试图GROUP BY“YEAR”但我得到一个

Error: Each GROUP BY expression must contain at least one column that is not an outer reference - which I assume is because I haven't linked the 2 tables in any way...

我应该加入UNION所以表的连接？

我希望看到的是类似如下的输出（我将在后面绘制了）

YEAR FORECAST ACTUAL 
2013 135000  127331 
2014 143000  145102 
2015 149000   0 
2016 158000   0 
2017 161000   0 
2018... etc 

任何帮助或指导将非常感激。 感谢

Answer 1

虽然语法很毛，这似乎是一个相当简单的查询。事实上，你连接你的两个表（使用JOIN语句）并且你不需要一个UNION。

尝试是这样的（使用公用表表达式，或者CTE，使分组更清晰，并改变了语法稍大清晰度）：

WITH data 
AS (
    SELECT YEAR = CAST((LEFT(A.TA_ANS_QUESTION,4)) AS INTEGER) 
     , FORECAST = CASE WHEN A.TA_ANS_QUESTION LIKE '%forecast' 
          THEN CONVERT(NUMERIC(9,2), A.TA_ANS_ANSWER) 
          ELSE CONVERT(NUMERIC(9,2), 0) 
         END 
     , ACTUAL = CASE WHEN A.TA_ANS_QUESTION LIKE '%actual' 
         THEN CONVERT(NUMERIC(9,2), ISNULL(A.TA_ANS_ANSWER,0)) 
         ELSE CONVERT(NUMERIC(9,2), 0) 
        END 
    FROM F_TASK_ANS A 
     INNER JOIN F_TASKS T 
      ON A.TA_ANS_FKEY_TA_SEQ = T.TA_SEQ 
    -- It sounded like you wanted to include the ones where the answer was null. If 
    -- that's wrong, get rid of the test for NULL. 
    WHERE (A.TA_ANS_ANSWER <> '' OR A.TA_ANS_ANSWER IS NULL) 
     AND (TA_TASK_ID LIKE '%6051' OR TA_TASK_ID LIKE '%6052') 
) 
    SELECT  YEAR 
     ,  FORECAST = SUM(data.Forecast) 
     ,  ACTUAL = SUM(data.Actual) 
    FROM  data 
    GROUP BY YEAR 
    ORDER BY YEAR 

Answer 2

尝试这样的事情......

SELECT CAST((LEFT(F_TASK_ANS.TA_ANS_QUESTION,4)) AS INT) AS [YEAR] 

     ,SUM(CAST((CASE WHEN F_TASK_ANS.TA_ANS_QUESTION LIKE '%forecast' 
     THEN F_TASK_ANS.TA_ANS_ANSWER ELSE 0 END) AS NUMERIC(9,2))) AS [FORECAST] 

    ,SUM(CAST((CASE WHEN F_TASK_ANS.TA_ANS_QUESTION LIKE '%actual' 
     THEN F_TASK_ANS.TA_ANS_ANSWER ELSE 0 END) AS NUMERIC(9,2))) AS [ACTUAL] 

FROM F_TASK_ANS INNER JOIN F_TASKS 
ON F_TASK_ANS.TA_ANS_FKEY_TA_SEQ = F_TASKS.TA_SEQ 
WHERE TA_ANS_ANSWER <> '' 
AND (TA_TASK_ID LIKE '%6051' OR TA_TASK_ID LIKE '%6052') 
GROUP BY CAST((LEFT(F_TASK_ANS.TA_ANS_QUESTION,4)) AS INT)