Squeel 和 rails... 动态 where 子句 [英] Squeel and rails... dynamic where clause
问题描述
使用 Squeel，在 Rails 应用程序中，我有一个条件散列:
Using Squeel, in a rails app, I have a hash of conditions:
{'trans' => 'manual'}
我最终计划移动到一个数组中...所以我也可以有一个运算符赋值.
which i eventually plan on moving into an array... so i can also have an operator assignment.
[[field,operator,value][field,operator,value]]
我想使用模型方法，现在我省略了操作符，我只是想 == 让它工作......但是，我下面的方法不起作用.
I want to use a Model method, which for now i omit the operator and am I just trying == to get this to work... however, what i have below does not work.
def self.with_conditions(conditions)
joins{car}.where do
conditions.map {|key,value| (key==value) }.inject(:&)
end
end
我也试过这个:
def self.with_conditions(conditions)
joins{car}.where do
query = nil
conditions.each do |key, value|
q = (key == value)
if query
query &= q
else
query = q
end
end
query
end
end
那么，我如何让它与 == 一起工作，然后我最终如何让它与动态运算符一起工作?谢谢
So, how do i get this to work with the ==, and then how would i eventually get this to work with a dynamic operator as well? thanks
在控制台中，我的 SQL 没有读取我的任何条件...例如:
In console, my SQL doesn't read in any of my conditions... for example:
在控制台中:
> Timeslip.with_conditions({'car.year'=>'1991'})
SELECT "timeslips".* FROM "timeslips" INNER JOIN "cars" ON "cars"."id" = "timeslips"."car_id"
推荐答案
您需要以编程方式构建 Squeel 查询.例如:
You need to programmatically build the Squeel query. For example:
def self.with_conditions(conditions)
conditions.map do |col, str|
Squeel::Nodes::Predicate.new(Squeel::Nodes::Stub.new(col), :matches, str) # (email.matches "user@example.com")
end.inject do |t, expr|
t & expr # joins each expression from the .map above with & - to be converted to AND in the sql
end.tap do |block|
return where{(block)} # pass the constructed expression to Squeel
end
end
在我的 User::User 模型上我可以运行
On my User::User model I can run
User::User.with_conditions({email: "user@example.com", first_name: "Deefour"}).to_sql
我会得到
SELECT "user_users".* FROM "user_users" WHERE (("user_users"."email" LIKE 'user@example.com' AND "user_users"."first_name" LIKE 'Deefour'))
这篇关于Squeel 和 rails... 动态 where 子句的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
