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  • Clickhouse 实现 row number功能

    参考博客:https://blog.csdn.net/qq_41018861/article/details/118723297

    1、建表

    CREATE TABLE default.row_number
    (
        `user_id` String,
        `user_phone` String,
        `create_time` DateTime,
        `update_time` DateTime
    )
    ENGINE = MergeTree
    ORDER BY user_id
    SETTINGS index_granularity = 8192;

    2、插入语句

    insert into default.row_number values
    ('1','13234567891','2021-07-14 11:54:19','2021-07-14 11:54:19'),
    ('1','13234567890','2021-07-14 11:40:09','2021-07-14 11:40:09'),
    ('1','13234567892','2021-07-14 11:54:37','2021-07-14 11:54:37'),
    
    ('2','13234567894','2021-07-14 11:57:22','2021-07-14 11:57:22'),
    ('2','13234567893','2021-07-14 11:55:05','2021-07-14 11:55:05'),
    ('3','13234567896','2021-07-14 11:57:45','2021-07-14 11:57:45'),
    ('3','13234567895','2021-07-14 11:57:30','2021-07-14 11:57:30')

    3、row number 取最新一条查询

    select user_id, 
          groupArray(1)(user_phone) AS user_phone,
          groupArray(1)(create_time) AS create_time,
          groupArray(1)(update_time) AS update_time
     from (select user_id, 
                  user_phone,
                  create_time,
                   update_time
             from default.row_number
            ORDER BY update_time desc
           ) a
    group by user_id
    order by user_id

    4、结果

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  • 原文地址:https://www.cnblogs.com/ywjfx/p/15743551.html
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