如何搜索包含特定單詞的行然後返回每個單詞的計數？

Question

我有150,000行數據，我試圖在Google BigQuery中查詢。

列Text包含各種長度的文本，我想從中查詢特定關鍵字。

我已經得到儘可能下面的查詢返回包含特定關鍵字（比如Facebook）的所有行：如何提高查詢

1）：

SELECT Text From Data.Set_1 
WHERE Text CONTAINS 'facebook' 

問題因此它會在新的列中的「文本」中返回所有關鍵字「臉譜」的總次數？ 2）如何將這個數據放大到多個關鍵字（Facebook，cnn，bbc，twitter）並返回數據中每個關鍵字的總數（例如facebook 42，cnn 54，bbc 88，twitter 49）？

Answer 1

爲BigQuery的傳統的SQL

SELECT 
    keyword, 
    COUNT(1) AS rows, 
    SUM(INTEGER((LENGTH(Text) - LENGTH(REPLACE(Text, keyword, '')))/LENGTH(keyword))) AS occurences 
FROM YourTable 
CROSS JOIN keywords 
WHERE Text CONTAINS keyword 
GROUP BY keyword 

實施例與

SELECT 
    keyword, 
    COUNT(1) AS rows, 
    SUM(INTEGER((LENGTH(Text) - LENGTH(REPLACE(Text, keyword, '')))/LENGTH(keyword))) AS occurences 
FROM (
    SELECT Text FROM 
    (SELECT 'facebookfacebookcnnbbccnn' AS Text), 
    (SELECT 'facebook' AS Text), 
    (SELECT 'cnn' AS Text) 
) AS words 
CROSS JOIN (
    SELECT keyword FROM 
    (SELECT 'facebook' AS keyword), 
    (SELECT 'cnn' AS keyword), 
    (SELECT 'bbc' AS keyword) 
) AS keywords 
WHERE Text CONTAINS keyword 
GROUP BY keyword 

對於大量查詢標準SQL播放（見Enabling Standard SQL）

SELECT 
    keyword, 
    COUNT(1) AS `rows`, 
    SUM((LENGTH(Text) - LENGTH(REPLACE(Text, keyword, '')))/LENGTH(keyword)) AS occurences 
FROM YourTable 
JOIN keywords 
ON STRPOS(Text, keyword) > 0 
GROUP BY keyword 

實施例與

打

Answer 2

您可以使用派生表包括所有你正在尋找的話，然後用聚集計數比賽：

SELECT w.keyword, COUNT(s.Text) 
From (SELECT 'facebook' as keyword UNION ALL 
     SELECT 'cnn' 
    ) w LEFT JOIN 
    Data.Set_1 s 
    ON s.Text CONTAINS w.keyword 
GROUP BY w.keyword; 

請注意：這不是特別有效。性能應該與關鍵字數量大致呈線性關係。