mysql - 不像不使用 Rails 在 MySQL 中工作

Question

>> Comment.count
  SQL (0.3ms)   SELECT count(*) AS count_all FROM `comments` 
=> 451
>> Comment.count(:conditions => ["author_website not like ?",'aaaa'])
  SQL (1.4ms)   SELECT count(*) AS count_all FROM `comments` WHERE (author_website not like 'aaaa') 
=> 203
>> Comment.count(:conditions => ["author_website like ?",'aaaa'])
  SQL (1.2ms)   SELECT count(*) AS count_all FROM `comments` WHERE (author_website like 'aaaa') 
=> 0
>> 

我预计 NOT LIKE 的计数为 451。

我正在使用 MySQL 和 Ruby on Rails。

Answer 1

author_website 是可为 null 的字段吗？

如果 248 行有空值，这可能可以解释。

你可以这样做吗？

Comment.count(:conditions => ["not(author_website like ?)",'aaaa'])