SQL Rails：如何通过包含特定字符串的字段查找
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Rails: How to find_by a field containing a certain string
提问by varatis
I have a model named Topic, that has a name as a field.
我有一个名为 Topic 的模型，它有一个名称作为字段。
So say I have a term I'm searching for, apple.
所以说我有一个我正在寻找的术语，苹果。
If I do a
如果我做一个
Topic.find_by_name("apple")
I get a record back with the name apple. That's good -- but how do I change find_by_name so that it can find "apple juice" as well as "apple" -- basically, find names that contain the original query or exactly match the original query?
我得到了一个名字为苹果的记录。这很好——但是我如何更改 find_by_name 以便它可以找到“apple juice”和“apple”——基本上，查找包含原始查询或与原始查询完全匹配的名称？
Edit:Thanks for all the response. I guess I should've been a little more clear earlier, but what if I want to find by a variable name (obviously I'm not going to want to find by the name "apple" everytime :) )?
编辑：感谢所有的回应。我想我应该早些时候更清楚一点，但是如果我想通过变量名查找怎么办（显然我不会每次都想通过名称“apple”来查找:)）？
How do I manipulate Topic.where to accommodate for this? So something like...
我如何操作 Topic.where 来适应这个？所以像...
@topic = Topic.where(......., @name)
回答by Deleteman
I think something like this should work:
我认为这样的事情应该有效：
Topic.where("name like ?", "%apple%")
To accomodate for your edit:
为了适应您的编辑：
Topic.where("name like ?", "%#{@search}%")
Basic string interpolation, you're using the value of @searchinside the string %%, so you @search = "apple"then you end up with %apple%
基本串插，你正在使用的值@search的字符串里面%%，所以你@search = "apple"那你结了 %apple%
回答by ScottJShea
回答by Alisher Ulugbekov
Don't put string directly like that. Its called SQL injection. You should instead use .where:
不要像那样直接放字符串。它被称为 SQL 注入。你应该改用.where：
Topic.where("name like '?%' ", params[:name])
回答by Szymon Rut
With PostgreSQL you can also use match operators:
使用 PostgreSQL，您还可以使用匹配运算符：
Topic.where("name ~* ?", @search)
回答by asitmoharna
Try
尝试
Topic.where("name like ?",'%apple%')
Topic.find(:all, :conditions => ["name like ?","%apple%"])
