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问题描述

我正在使用 ransack gem 进行Rails搜索。我需要在 User 表中搜索 email_ids 的数组。

I'm using ransack gem for searching in rails application. I need to search an array of email_ids in User table.

在洗劫案中引用问题,我按照步骤操作并添加了这到初始化文件夹 ransack.rb

Referring to this issue at ransacking, I followed the steps and added this to the initializers folder ransack.rb

Ransack.configure do |config|
   {
    contained_within_array: :contained_within,
    contained_within_or_equals_array: :contained_within_or_equals,
    contains_array: :contains,
    contains_or_equals_array: :contains_or_equals,
    overlap_array: :overlap
   }.each do |rp, ap|
   config.add_predicate rp, arel_predicate: ap, wants_array: true
  end
end

在rails控制台中,如果我这样做:

In the rails console, if i do like this:

a = User.search(email_contains_array: ['[email protected]'])

它生成如下所示的sql:

it produces the sql like this:

"SELECT \"users\".* FROM \"users\" WHERE \"users\".\"deleted_at\" IS NULL AND (\"users\".\"email\" >> '---\n- [email protected]\n')"

并给出如下错误:

  User Load (1.8ms)  SELECT "users".* FROM "users" WHERE "users"."deleted_at" IS NULL AND ("users"."email" >> '---
- [email protected]
')
 ActiveRecord::StatementInvalid: PG::UndefinedFunction: ERROR: operator does not exist: character varying >> unknown
 LINE 1: ...RE "users"."deleted_at" IS NULL AND ("users"."email" >> '---
                                                            ^
 HINT:  No operator matches the given name and argument type(s). You might need to add explicit type casts.
 : SELECT "users".* FROM "users" WHERE "users"."deleted_at" IS NULL AND ("users"."email" >> '---
 - [email protected]
')

此查询预期为:

SELECT "users".* FROM "users"  WHERE ("users"."roles" @> '{"3","4"}')

我在做什么错?

推荐答案

我遇到了与您相同的问题,我正在使用Rails 5,需要在 User 表中搜索角色的数组

I met the same problem as you do. I'm using Rails 5, and I need to search an array of roles in User table

似乎您已经在自己的gemfile中添加了 postgres_ext gem ,但是如果在Rails 5应用程序中使用它,则会出现一些问题。

It seems that you have already add postgres_ext gem in your gemfile, but it has some problems if you are using it in Rails 5 application.

就这样是您自己在Arel Node中添加包含查询的一种选择,而不是使用 postgres_ext gem

So it is a choice for you to add a contain query in Arel Node by yourself instead of using postgres_ext gem

如果您使用的是其他版本的Rails,我认为它也很好用。

And if you are using other version of Rails, I think it works well too.

我有一个 User 模型,以及数组属性 roles 。我想做的是使用 ransack 搜索角色

I have an User model, and an array attribute roles. What I want to do is to use ransack to search roles. It is the same condition like yours.

流袋无法搜索数组。
但是 PostgresSQL 可以像这样搜索数组:

ransack can't search array.But PostgresSQL can search array like this:

User.where( roles @>?,'{admin}')。to_sql)

它会生成如下所示的sql查询:

it produce the sql query like this:

SELECT "users".* FROM "users" WHERE "users"."deleted_at" IS NULL AND (roles @> '{admin}')

所以我要做的是在<$ c $中添加类似的包含查询c> Arel节点

您可以做到:

# app/config/initializers/arel.rb

require 'arel/nodes/binary'
require 'arel/predications'
require 'arel/visitors/postgresql'

module Arel
  class Nodes::ContainsArray < Arel::Nodes::Binary
    def operator
      :"@>"
    end
  end

  class Visitors::PostgreSQL
    private

    def visit_Arel_Nodes_ContainsArray(o, collector)
      infix_value o, collector, ' @> '
    end
  end

  module Predications
    def contains(other)
      Nodes::ContainsArray.new self, Nodes.build_quoted(other, self)
    end
  end
end

因为您可以自定义ransack谓词,
,因此添加包含 Ransack谓词,例如:

Because you can custom ransack predicate,so add contains Ransack predicate like this:

# app/config/initializers/ransack.rb

Ransack.configure do |config|
  config.add_predicate 'contains',
    arel_predicate: 'contains',
    formatter: proc { |v| "{#{v}}" },
    validator: proc { |v| v.present? },
    type: :string
end

完成!

现在,您可以搜索数组:

Now, you can search array:

User.ransack(roles_contains: 'admin')

SQL查询如下:

SELECT \"users\".* FROM \"users\" WHERE \"users\".\"deleted_at\" IS NULL AND (\"users\".\"roles\" @> '{[\"admin\"]}')

是的!

这篇关于如何通过ransack gem搜索数组?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!

09-12 13:02