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如何在mysql中编写更新查询?_Mysql_Ruby On Rails_Ruby On Rails 3 - Fatal编程技术网

如何在mysql中编写更新查询?

如何在mysql中编写更新查询?,mysql,ruby-on-rails,ruby-on-rails-3,Mysql,Ruby On Rails,Ruby On Rails 3,我想更新我的所有这些记录,得到上述查询。我想更新来自上述查询的结果的状态id 我该怎么做 请帮助我。请测试此代码: select email, status_id, count(*) from customers group by email, status_id having count(*) > 1; 更新客户 设置customers.status\u id= 案例 当计数(*)大于1时,则为“值1” 当计数(*)=1时 希望对您有所帮助首先,用什么更新status\u id?第二

我想更新我的所有这些记录,得到上述查询。我想更新来自上述查询的结果的状态id

我该怎么做


请帮助我。

请测试此代码:

select email, status_id, count(*) from customers group by email, status_id having count(*) > 1;
更新客户
设置customers.status\u id=
案例
当计数(*)大于1时,则为“值1”
当计数(*)=1时

希望对您有所帮助

首先,用什么更新
status\u id
?第二,要更新同一个表吗?
UPDATE customers
SET customers.status_id = 
   CASE
     When COUNT(*) >1 Then 'value 1'
     When COUNT(*) <1 Then 'value 2'
     When COUNT(*) = 1 Then 'value 3'
     ELSE 'SARB'
   END  
GROUP BY email, status_id
HAVING COUNT(*) >= 1