在Rails ActiveRecord中将where子句与join子句一起使用
[英]Using a where clause with join clause in Rails activerecord
问题描述
I want to do a join query with a where clause, but I'm getting a syntax error. 
我想使用where子句进行联接查询，但是出现语法错误。
What is the correct syntax for using a where clause with a joins? 将where子句与联接一起使用的正确语法是什么？
The Rails docs gives an example using a hash with a single join, but can't find one similar to my problem. Rails的文档给出了一个示例，该示例使用具有单个联接的哈希，但是找不到与我的问题类似的哈希。
Query: 查询：
User.joins("user_tags").joins("tags").where("tags.value <> 'single'")
Error: 错误：
ActiveRecord::StatementInvalid: PG::SyntaxError: ERROR: syntax error at or near "tags"
LINE 1: ...LECT "users".* FROM "users" user_tags tags...
1 个解决方案
解决方案1
4 2015-07-19 20:37:41
You can define in your user model 您可以在用户模型中定义
has_many :user_tags
has_many :tags, through: :user_tags
and then just use 然后就用
User.joins(:tags).where.not(tags: { value: 'single' })
声明:本站的技术帖子网页，遵循CC BY-SA 4.0协议，如果您需要转载，请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.
相关问题
Rails ActiveRecord where或clause - Rails ActiveRecord where or clause
Rails ActiveRecord where子句 - Rails ActiveRecord where clause
Rails: Or & and in Rails ActiveRecord where 子句 - Rails: Or & and in Rails ActiveRecord where clause
Rails ActiveRecord where子句不起作用 - Rails ActiveRecord where clause not working
构建 Rails ActiveRecord where 子句 - Constructing a Rails ActiveRecord where clause
使用函数的ActiveRecord'where'子句 - ActiveRecord 'where' clause using function
Rails ActiveRecord在join子句中的转义变量 - Rails ActiveRecord escape variable in join clause
多个包含ActiveRecord Rails的where子句 - Multiple where clause with include ActiveRecord Rails
在ActiveRecord的Rails“ include”中添加“ where”子句 - Adding a “where” clause to Rails “include” in ActiveRecord
Rails 6 ActiveRecord 和 where 子句中的列 - Rails 6 ActiveRecord sum columns in where clause
相关标签