AWS ATHENA:用户定义的变量 [英] AWS ATHENA: user-defined variables

问题描述

我需要按组创建一个行号.在 mysql 中，我为此使用用户定义的变量".但是在 Athena 中给了我一个错误:在输入 '@' 处没有可行的替代方案

I need to create a row number by group. In mysql I use "user-defined variables" for that. But in Athena is gives me an error: no viable alternative at input '@'

这是我的查询:

SELECT  @row_num := IF(@prev_value=concat_ws('',t.user_id,t.campaign_id,t.placement_id, t.creative_id),@row_num+1,1) AS RowNumber
     ,t.user_id 
     ,t.campaign_id
     ,t.placement_id
     ,t.creative_id
     , t.imp_clk_event_dt
     ,@prev_value := concat_ws('',t.user_id,t.campaign_id,t.placement_id, t.creative_id)
FROM e2c_conv t,
     (SELECT @row_num := 1) x,
     (SELECT @prev_value := '') y ORDER BY t.user_id,t.campaign_id,t.placement_id, t.creative_id, t.imp_clk_event_dt

对于如何解决此问题的任何建议，我们将不胜感激.

Any suggestions on how to resolve this problem will be highly appreciated.

推荐答案

TLDR:AWS Athena 不支持变量.

TLDR: AWS Athena does not support variables.

根据他们的文档，AWS Athena 基于 Presto 0.172 和一些 限制.Presto 当前有一个未解决的问题，正在讨论添加变量.PR-5918

As per their documentation, AWS Athena is based on Presto 0.172 with some limitations. Presto currently has an open issue where the addition of variables is being discussed. PR-5918

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