選擇數據範圍爲指定的列的SQL Server

Question

我不得不選擇從SQL Sever的表中多個日期範圍即數據

1990-1994, 1992-1996, 1994-1998, 1996-2000, 1998-2002, 2000-2004, 
2002-2006, 2004-2008, 2006-2010, 2008-2012, 2010-2014 

我已經使用這個查詢來獲取無DATE範圍數據即

SELECT 
    aid, research_area_category_id, 
    CAST(research_area as VARCHAR(100)) [research_area], 
    COUNT(*) [Counting] 
FROM 
    sub_aminer_paper 
GROUP BY 
    CAST(research_area as VARCHAR(100)), aid, research_area_category_id 
HAVING 
    aid = 12403 
ORDER BY 
    Counting DESC 

這給出輸出作爲圖像即

現在對於使用WHERE子句的每個DATE範圍，我必須在DATE範圍的相應列中顯示數據。雖然我已經使用這個查詢即

SELECT 
    aid, research_area_category_id, 
    [research_area] = CAST(research_area as VARCHAR(100)), 
    [Counting] = COUNT(*), 
    [1990 - 1994] = SUM(CASE WHEN p_year BETWEEN 1990 AND 1994 THEN 1 ELSE 0 END), 
    [1992 - 1996] = SUM(CASE WHEN p_year BETWEEN 1992 AND 1996 THEN 1 ELSE 0 END), 
    [1994 - 1998] = SUM(CASE WHEN p_year BETWEEN 1994 AND 1998 THEN 1 ELSE 0 END), 
    [1996 - 2000] = SUM(CASE WHEN p_year BETWEEN 1996 AND 2000 THEN 1 ELSE 0 END), 
    [1998 - 2002] = SUM(CASE WHEN p_year BETWEEN 1998 AND 2002 THEN 1 ELSE 0 END), 
    [2000 - 2004] = SUM(CASE WHEN p_year BETWEEN 2000 AND 2004 THEN 1 ELSE 0 END), 
    [2002 - 2006] = SUM(CASE WHEN p_year BETWEEN 2002 AND 2006 THEN 1 ELSE 0 END), 
    [2004 - 2008] = SUM(CASE WHEN p_year BETWEEN 2004 AND 2008 THEN 1 ELSE 0 END), 
    [2006 - 2010] = SUM(CASE WHEN p_year BETWEEN 2006 AND 2010 THEN 1 ELSE 0 END), 
    [2008 - 2012] = SUM(CASE WHEN p_year BETWEEN 2008 AND 2012 THEN 1 ELSE 0 END), 
    [2010 - 2014] = SUM(CASE WHEN p_year BETWEEN 2010 AND 2014 THEN 1 ELSE 0 END) 
FROM 
    sub_aminer_paper 
WHERE 
    aid = 2937 
    AND p_year BETWEEN 1990 AND 2014    
GROUP BY 
    aid, CAST(research_area AS VARCHAR(100)), research_area_category_id 
ORDER BY aid ASC, Counting DESC 

而這個查詢輸出這樣的：

，但我需要下（1990- 1994年，1992- 1996年，1994- 1998年research_area_category_id值...這些專欄。例如。在1990 - 1994柱，它應該顯示各research_area_category_id即1，1和32代替Counting即1，1和1，類似地它應該顯示33代替2在1998 - 2002柱，反之亦然。

請幫助和提前致謝。

Answer 1

標籤Alleman已經提到在評論中這裏最好的辦法，但我要厚臉皮，並將其添加作爲一個答案。

你是清楚的，你想在你的轉動日期列顯示來自research_area_category_id列值。因此，第一步這裏是讓research_area_category_id每個CASE語句的輸出，而不是一個整數1：

CASE WHEN p_year BETWEEN 1990 AND 1994 THEN research_area_category_id ELSE 0 END 

如果你只是這種變化跑出你的代碼，你會發現SUM功能使輸出爲倍數值爲research_area_category_id。例如，1998 - 2002的第一行將具有值66（兩倍33）。

所以這告訴我們，你不希望使用SUM功能了。但是，您仍然希望在具有不同的p_year值的所有行上聚合（分組）數據，因此您必須改用某種類型的聚合函數。如果你沒有，SQL Server會拋出一個錯誤，因爲你沒有按p_year分組。

最簡單的集合函數在這種情況下使用的是MAX，其從組行取最高值被分組成一個。 official documentation有一些簡單的例子。

這隻適用於您的情況，前提是research_area_category_id的所有值都是正數（大於CASE語句默認設置的0），它們似乎是。

結合變向CASE語句從SUM到MAX的變化給你的查詢以下版本：

SELECT 
aid, research_area_category_id, 
[research_area] = CAST(research_area as VARCHAR(100)), 
[Counting] = COUNT(*), 
[1990 - 1994] = MAX(CASE WHEN p_year BETWEEN 1990 AND 1994 THEN research_area_category_id ELSE 0 END), 
[1992 - 1996] = MAX(CASE WHEN p_year BETWEEN 1992 AND 1996 THEN research_area_category_id ELSE 0 END), 
[1994 - 1998] = MAX(CASE WHEN p_year BETWEEN 1994 AND 1998 THEN research_area_category_id ELSE 0 END), 
[1996 - 2000] = MAX(CASE WHEN p_year BETWEEN 1996 AND 2000 THEN research_area_category_id ELSE 0 END), 
[1998 - 2002] = MAX(CASE WHEN p_year BETWEEN 1998 AND 2002 THEN research_area_category_id ELSE 0 END), 
[2000 - 2004] = MAX(CASE WHEN p_year BETWEEN 2000 AND 2004 THEN research_area_category_id ELSE 0 END), 
[2002 - 2006] = MAX(CASE WHEN p_year BETWEEN 2002 AND 2006 THEN research_area_category_id ELSE 0 END), 
[2004 - 2008] = MAX(CASE WHEN p_year BETWEEN 2004 AND 2008 THEN research_area_category_id ELSE 0 END), 
[2006 - 2010] = MAX(CASE WHEN p_year BETWEEN 2006 AND 2010 THEN research_area_category_id ELSE 0 END), 
[2008 - 2012] = MAX(CASE WHEN p_year BETWEEN 2008 AND 2012 THEN research_area_category_id ELSE 0 END), 
[2010 - 2014] = MAX(CASE WHEN p_year BETWEEN 2010 AND 2014 THEN research_area_category_id ELSE 0 END) 
FROM 
    sub_aminer_paper 
WHERE 
    aid = 2937 
    AND p_year BETWEEN 1990 AND 2014    
GROUP BY 
    aid, CAST(research_area AS VARCHAR(100)), research_area_category_id 
ORDER BY aid ASC, Counting DESC 

如果你有興趣，我嘲笑了像你這樣的數據的幾行在this SQL fiddle之前在回答之前測試此查詢。 （我猜在p_year值，但他們證明的原則，除非我誤解你的要求。）