按带 * 通配符的条件查找

发布于 2024-12-28 21:37:33 字数 431 浏览 3 评论 0原文

我有一个带有两个参数的搜索表单。如果参数为空，我想搜索全部。

var_1 = params[:var_1].blank? ? "*" : params[:var_1]
var_2 = params[:var_2].blank? ? "*" : params[:var_2]

@mymodels = MyModel.find(:all,:conditions=>["var_1 = ? and var_2 = ?",var_1,var_2])

这就是我得到的：

SELECT ... WHERE (var_1 = '*' and ...

我需要的是：

SELECT ... WHERE (var_1 = * and ...

有什么建议吗？

原文

I have a search form with two params. If a param is empty I'd like to search all.

var_1 = params[:var_1].blank? ? "*" : params[:var_1]
var_2 = params[:var_2].blank? ? "*" : params[:var_2]

@mymodels = MyModel.find(:all,:conditions=>["var_1 = ? and var_2 = ?",var_1,var_2])

This is what I got:

SELECT ... WHERE (var_1 = '*' and ...

what I need is:

SELECT ... WHERE (var_1 = * and ...

Any suggestions?

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∞琼窗梦回ˉ 2025-01-04 21:37:33

我会有条件地建立标准清单。即如果相应参数不为空，则仅在查询中包含一个字段：

conditions = []
values = []
[:var1, :var2].each do |field|
  unless params[field].blank?
    conditions << "#{field} = ?"
    values << params[:field]
  end
end

然后运行find：

MyModel.find(:all, :conditions => [conditions.join(" AND "), values])

I would build up the list of criteria conditionally. i.e. only include a field in the query if the corresponding parameter is not blank:

conditions = []
values = []
[:var1, :var2].each do |field|
  unless params[field].blank?
    conditions << "#{field} = ?"
    values << params[:field]
  end
end

and then run the find:

MyModel.find(:all, :conditions => [conditions.join(" AND "), values])

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酷到爆炸 2025-01-04 21:37:33

我会考虑建立一个可修改的查询，因为 arel 是建立在这个想法之上的。

例如，

query = Model.scoped
query = query.where(:var1 => params[:var1]) if params[:var1].present?
query = query.where(:var2 => params[:var2]) if params[:var2].present?
... more conditions
@models = query.all # returns the array, finally

我在这里使用 Model::scoped 以便能够继续我的搜索，因为它
返回一个 ActiveRecord::Relation 对象，而不是像 Model.all 这样的数组
会。

我发现开始广泛搜索然后缩小范围很有帮助。

希望它有帮助，

-卢克

I would look into building up a modifiable query, as arel is built upon this idea.

For example,

query = Model.scoped
query = query.where(:var1 => params[:var1]) if params[:var1].present?
query = query.where(:var2 => params[:var2]) if params[:var2].present?
... more conditions
@models = query.all # returns the array, finally

I used Model::scoped here to be able to continue my searches, because it
returns an ActiveRecord::Relation object, and not an array like Model.all
would.

I've found it helpful to start broad searches and then narrow them down.

Hope it helps,

-Luke

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遮了一弯 2025-01-04 21:37:33

我想 SELECT ... WHERE (var_1 = * and ... 无论如何都行不通，因为你需要的是一个 like 子句，

例如： SELECT ... WHERE var_1 like '%' 和 ...

所以一个选择应该是，有一个单独的方法：

例如：

def mymodel_list(var1, var2)
  @mymodels = nil
  if var1 && var2
    @mymodels = MyModel.find(:all,:conditions=>["var_1 = ? and var_2 = ?",var_1,var_2])
  else
    @mymodels = MyModel.find(:all) 
  end  
  @mymodels
end

IMO，有时最好编写更多代码，以便逻辑可以轻松管理。

I guess having SELECT ... WHERE (var_1 = * and ... will not work anyway, as what you need there is a like clause,

Ex: SELECT ... WHERE var_1 like '%' and ...

So one option should be, have a separate method:

Ex:

def mymodel_list(var1, var2)
  @mymodels = nil
  if var1 && var2
    @mymodels = MyModel.find(:all,:conditions=>["var_1 = ? and var_2 = ?",var_1,var_2])
  else
    @mymodels = MyModel.find(:all) 
  end  
  @mymodels
end

IMO, sometimes it better to write more code, so that the logic can manage easily.

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