您如何在dotnet Core中使用DBContext [英] How do you just use a DBContext in dotnet Core

问题描述

所以可以说我只是创建一个帮助器类，需要从静态方法内部调用数据库。

 没有给出与'ApplicationDbContext.ApplicationDbContext（DbContextOptions< ‌ 
 ApplicationDbContext‌>）''
 的所需形式参数
'options'相对应的参数pre> 
 
 
我似乎无法做到
 公共静态bool IsKeyValid（字符串键）
 {
 var isValid = false; 
 
 if（！String.IsNullOrEmpty（key））{
 isValid = new ApplicationDbContext（）。Children.Any（x => x.Token == key）; 
} 
 
返回isValid; 
} 
  
所以我知道我可以从控制器获取上下文并将其传递给我，但这是唯一的方法吗？
 
 
 
我很困惑，因为所有文档都说嘿，创建一个新的上下文，看看它有多容易 
  
解决方案
如果需要手动创建上下文，则可以如下所示进行配置
  var options = new DbContextOptionsBuilder< ApplicationDbContext>（）;。 
选项。UseSqlServer（Configuration.GetConnectionStringSecureValue（ DefaultConnection））; 
 _context =新的ApplicationDbContext（options.Options）; 
  
也请参见： 配置DbContext   
 
So lets say I just make a helper class and need to call the DB from inside a Static Method.
There is no argument given that corresponds to the required formal parameter 
'options' of 'ApplicationDbContext.ApplicationDbContext(DbContextOptions<‌​
ApplicationDbContext‌​>)' 
I can't seem to just do
    public static bool IsKeyValid(string key)
    {
        var isValid = false;

        if (!String.IsNullOrEmpty(key)) {
            isValid = new ApplicationDbContext().Children.Any(x => x.Token == key);
        }

        return isValid;
    }
So I know I can get my context from my controller and pass it in, but is that the only way?

I'm very confused because all the docs just kinda say "Hey, make a new context, look how easy it is"
http://ef.readthedocs.io/en/latest/querying/basic.html#id3

Any help would be appreciated

解决方案
If you need to create the context manually, then you can configure it as shown below.
var options = new DbContextOptionsBuilder<ApplicationDbContext>();
options.UseSqlServer(Configuration.GetConnectionStringSecureValue("DefaultConnection"));
_context = new ApplicationDbContext(options.Options); 
Please see this too : Configuring a DbContext

                        
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