如何使用Dapper.Contrib通过唯一键获取实体? [英] How to Get entity by Unique Key using Dapper.Contrib?

问题描述

我有一个对象，假设

public class User
{
    [Key]
    int TheId { get; set; }
    string Name { get; set; }
    int Age { get; set; }
}

TheId 是我的自动增量列，而 Name 是我的唯一键.保存用户时，我想通过以下方式检查其存在:

TheId is my auto increment column and Name is my unique key. When saving a user, I want to check its existence by:

var user= connection.Get<User>("John");

但是，由于我的密钥不是 Name ，而是 TheId ，因此我无法执行此操作.如果我将 Name 属性设置为 [KeyExplicit] ，那么我想通过以下方式保存用户:

But, because of my Key is not Name but TheId, I can't do this. If I set Name property as [KeyExplicit] that time when I want to save my user by:

connection.Insert(myUser);

这一次，精打细算的人希望我填写 TheId 属性，而不是让数据库自动递增.

This time, dapper expect TheId property filled by me, not let database to auto increment.

因此，我想知道是否有一种优雅的方法可以实现在db上搜索时将一些属性标记为精简版要考虑的属性.我不想按 Guid 进行搜索，而是按唯一键进行搜索.

So, I wonder is there an elegant way to achieve to mark some property or properties to dapper take into account while searching on db. I don't want to search by Guid but unique keys.

推荐答案

如果我理解正确，那么您愿意

If I understood correctly, you are willing to Get by property other than key.

dapper-contrib不支持此功能.对于 Get ，您应仅使用键字段.即使该其他属性是唯一键，也是不可能的.您所做的任何其他调整(在 Name 属性上设置 [KeyExplicit] )都不是解决此问题的正确方法.如您所见，它还会产生其他问题.

This is not supported by dapper-contrib. For Get, you should use key field only. This is not possible even if that other property is unique key. Any other adjustments you are doing (setting [KeyExplicit] on Name property) is not the proper way to handle this; it will create other problems as you can see.

对于具有其他属性的 Get ，更好的选择是直接绕过Contrib使用Dapper.

For Get with other properties, better alternative is to use Dapper directly bypassing Contrib.

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