SQL：有條件求和

Question

我建立了一個查詢，以將公司的銷售統計數據與其他公司進行比較。

簡化后，就像：

SELECT SUM(CASE WHEN company=foobar THEN sales ELSE 0) as sales_foobar,
SUM(sales) as sales_total, country, year, product FROM sales_table
GROUP BY country, year, product HAVING (the above sum again) > 0

遵從性規則要求僅顯示公司有任何銷售的行，而我的代碼將丟棄foobar沒有銷售的行，但由於訂單和退款相等，它也會丟棄銷售為0的行。

現在，我如何才能只獲得公司擁有銷售數據的行？

Answer 1

您可以在HAVING子句中計算與公司匹配的行數：

SELECT SUM(CASE WHEN company = foobar THEN sales ELSE 0 END) as sales_foobar,
       SUM(sales) as sales_total, country, year, product
FROM sales_table
GROUP BY country, year, product
HAVING SUM( company = foobar ) > 0;  -- there is at least one record for the company

Answer 2

您應該使用Where：

   SELECT SUM(CASE WHEN company=foobar THEN sales ELSE 0) as sales_foobar,
    SUM(sales) as sales_total, country, year, product 
    FROM sales_table
    Where sales > 0
    GROUP BY country, year, product HAVING (the above sum again) > 0

Answer 3

假設公司='foobar，根據您的問題進行計算即可； 您幾乎只在代碼中完成了答案。 因此，如果您需要除此以外的任何其他特定條件，請告訴我。 我會編輯答案。

SELECT 
    SUM (CASE WHEN company='foobar' THEN sales ELSE 0 end) as sales_foobar,
    SUM(sales) as sales_total, 
    country, 
    year, 
    product 
        FROM sales_table
            GROUP BY country, year, product 
                HAVING SUM (CASE WHEN company='foobar' THEN sales ELSE 0 end) > 0