SQL - 2個表值按第三個未連接值分組

Question

我想創建一個圖表，用於從SQL數據庫中生成的2個用戶問題中提取數據。

問題是用戶問題與答案一樣存儲在同一個表中。唯一的連接是問題字符串包含年份值，我使用命令提取的年份值，以便輸出一個名爲'YEAR'的列，列中包含從2013年到2038年（25年期間）的整數值列表， 。 然後，我想從每個'YEAR'拉相應的答案（'預測'和'實際'），以便我可以繪製一個圖表與每年的幾個值（抱歉，如果這沒有任何意義）。圖表應顯示25年期間的預測線，第二行（或列）顯示多年來人口填充時的實際值。然後我就能夠想象，如果我們的實際值是接近我們原來的預測數字（長期目標！）

下面的代碼

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 

我試圖GROUP BY「YEAR」但我得到一個

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...

我應該加入UNION所以表的連接？

我希望看到的是類似如下的輸出（我將在後面繪製了）

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

任何幫助或指導將非常感激。 感謝

Answer 1

雖然語法很毛，這似乎是一個相當簡單的查詢。事實上，你連接你的兩個表（使用JOIN語句）並且你不需要一個UNION。

嘗試是這樣的（使用公用表表達式，或者CTE，使分組更清晰，並改變了語法稍大清晰度）：

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

嘗試這樣的事情......

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)