SQL：在Chartio中動態地移動列作爲行

Question

我很想將您的幫助轉換爲連接此表的列。我試圖讓項目名稱（第1列）成爲它們自己的列標題，並輸入作爲列值的MUV值。

我已閱讀了關於此主題的20多個主題，但他們正在使用不同的SQL程序包和我無法使用的代碼。

理想的解決辦法修改這個查詢，以創建所需的查詢輸出：

當前查詢：

SELECT 
    cust_gae_account.project_name as "Project Name", 
    cust_be_project_usage.unique_visitor_count as "MUVs", 
    cust_be_project_usage.billing_period_start as "Month" 
FROM 
    cust_be_project_usage 
INNER JOIN 
    cust_gae_account 
    ON cust_gae_account.account_id = cust_be_project_usage.project_id 
WHERE 
    cust_be_project_usage.admin_account_id = {ACCOUNT_ID} 

當前查詢輸出：

Project Name  |  MUVs  |  Month 
----------------------------------------------------- 
ProjectAAAAAZ |  68000  | Jun 01, 2016 
DynamicName  |  3200  | Jun 01, 2016 
ProjectAAAAAZ |  21000  | May 01, 2016 
DynamicName  |  4500  | May 01, 2016 
CustomProject |  117000  | Jun 01, 2016 
CustomProject |  118400  | May 01, 2016 

所需的查詢輸出：

Project Name  | CustomProject | ProjectAAAAAZ | DynamicName 
------------------------------------------------------------------- 
Jun 01, 2016  |  117000  |  68000  |  3200 
May 01, 2016  |  118400  |  21000  |  4500 

注：

• 我們通過Chartio使用PostgreSQL，我們只能使用基本SQL
• 我們不能使用自定義功能，遺憾的是
• 名稱和項目數量是動態的，從1到20不等
• MUV總是數字，沒有重複

Answer 1

您可以使用交叉表https://www.postgresql.org/docs/9.1/static/tablefunc.html，但它僅適用於列的靜態列表。所以你需要一個動態查詢。您需要定義該查詢並執行它。

EXECUTE ('SELECT * FROM crosstab(
    \'SELECT 
     cust_be_project_usage.billing_period_start as "Month", 
     cust_gae_account.project_name as "Project Name", 
     cust_be_project_usage.unique_visitor_count as "MUVs" 
    FROM 
     cust_be_project_usage 
    INNER JOIN 
     cust_gae_account 
     ON cust_gae_account.account_id = cust_be_project_usage.project_id 
    WHERE 
     cust_be_project_usage.admin_account_id = {ACCOUNT_ID}\', 
    \'SELECT 
     cust_gae_account.project_name as "Project Name" 
    FROM 
     cust_be_project_usage 
    INNER JOIN 
     cust_gae_account 
     ON cust_gae_account.account_id = cust_be_project_usage.project_id 
    WHERE 
     cust_be_project_usage.admin_account_id = {ACCOUNT_ID}\') 
AS ("Project Name" date, ' || 
    (SELECT 
     string_agg(cust_gae_account.project_name, ' int,') 
    FROM 
     cust_be_project_usage 
    INNER JOIN 
     cust_gae_account 
     ON cust_gae_account.account_id = cust_be_project_usage.project_id 
    WHERE 
     cust_be_project_usage.admin_account_id = {ACCOUNT_ID}) || ' int' 
|| ')') 

雖然我無法測試它。它應該工作，但我的懷疑是，它可能沒有，在這種情況下：

1. 串聯到由查詢所形成的標量（可能需要使用一個變量爲一個）
2. 我可能已經混了一列某處
3. 不知道如何傳遞{ACCOUNT_ID}參數，所以你可能需要太