如何优化这个GORM查询 [英] How to optimize this GORM query

问题描述

我有一个查询，它使2个数据库查询。我是GORM的新手，不知道如何使用标准或where子句或其他方法将其优化为1个查询。我也使用springsecurity，并有一个用于登录安全性的User类。我有一个带User对象的Profile类：

  class Profile {
用户用户
} 
  

在我的控制器中，会话存储用户标识。当我想加载配置文件来更新它时，我的代码是：

$ p $ def $ user $ User.get（springSecurityService.principal。 id）//第一个数据库查询
def domainObject = Profile.findByUser（user）//第二个数据库查询

我通过试验和错误尝试了一些查询变体，但似乎无法找到不会产生错误的变体。这似乎是微不足道的。伪查询应该是'让我获得具有该用户标识的profile.user的配置文件'。

解决方案

您可以使用 load 方法避免第一个数据库查询：

  def user = User.load（springSecurityService.principal.id）
 def domainObject = Profile.findByUser（user）
  

因为 load 不会触发数据库查找，除非您访问 id 以外的任何其他属性，但这就是 findByUser 所需的全部内容，因为它是外键。

I have a query which makes 2 database queries. I am new to GORM and don't know how to optimize it into 1 query using criteria, or a where clause or something else. I'm using springsecurity as well and have a User class for login security. I have a Profile class with a User object:

class Profile {
   User user
}

In my controller the session stores the user id. When I want to load the profile to update it my code is currently:

def user = User.get(springSecurityService.principal.id) // 1st db query
def domainObject = Profile.findByUser(user) // 2nd db query

I've tried a few query variations through trial and error but can't seem to find one that doesn't generate an error. This seems like it would be trivial. The pseudo-query would be 'get me the profile for the profile.user that has this user id'.

解决方案

You can use the load method to avoid the first database query:

def user = User.load(springSecurityService.principal.id)
def domainObject = Profile.findByUser(user)

This works because load doesn't trigger a database lookup until you access any property other than the id, but that's all that's needed for the findByUser since it's the foreign key.

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