Databend 开源周报第 137 期

SELECT id, score(), content FROM t WHERE match(content, '中国') ORDER BY score()
----
21 1.1967509 中国的古代诗词充满了深邃的意境和独特的韵味，是中华文化的重要组成部分。
24 1.1967509 中国的传统节日蕴含着丰富的文化内涵，是传承和弘扬中华文化的重要途径。
28 1.3336442 中国的饮食文化博大精深，各地的美食各具特色，让人流连忘返。
12 1.4319203 北京的故宫是中国古代建筑的瑰宝，吸引了无数游客前来参观。
15 1.5059 中国的茶文化源远流长，品茶已经成为一种生活方式。

-- Define a task in Databend
CREATE TASK user_activity_task
WAREHOUSE = 'default'
SCHEDULE = 1 MINUTE
-- Trigger task when new data arrives in activities_stream
WHEN stream_status('activities_stream') AS
    -- Insert new records into user_activity_profiles
    INSERT INTO user_activity_profiles
    SELECT
        -- Join activities_stream with user_profiles based on user_id
        a.user_id, p.username, p.location, a.activity, a.timestamp
    FROM
        activities_stream AS a
        JOIN user_profiles AS p
            ON a.user_id = p.user_id
    -- Include only rows where the action is 'INSERT'
    WHERE a.change$action = 'INSERT';

SELECT ...
FROM ...
   CHANGES ( INFORMATION => { DEFAULT | APPEND_ONLY } )
   AT ( { TIMESTAMP => <timestamp> | OFFSET => <time_difference> | STREAM => '<name>' } )
   [ END( { TIMESTAMP => <timestamp> | OFFSET => <time_difference> } ) ]
[ ... ]