Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
755 views
in Technique[技术] by (71.8m points)

c# - How do I select correct DbSet in DbContext based on table name

Say I have a DbContext with the following DbSets

class Amimals : DbContext
{
    public DbSet<Dog> Dogs { get; set; }
    public DbSet<Cat> Cats { get; set; }
}

Inside of each EntityTypeConfiguration I am defining the table for each DbSet like

class DogConfig : EntityTypeConfiguration
{
    public DogConfig()
    {
        this.ToTable("DOG_TABLE");
        ...
    }
}

Now, if I have the table name and the DbContext, how can I grab and use the correct DbSet?

void foo()
{
    string tableName = this.GetTableName();
    using(Animals context = new Animals())
    {
        /* Made up solution */
        DbSet animalContext = context.Where(c => c.TableName == tableName);
        ...
        /* Do something with DbSet */
        ...
    }
}
See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

You can get DbSet from DbContext by Type using the method DbContext.Set(Type entityType). So if you have the model class name as string you should do some mapping to actual clr type.

For example:

string tableName = "Cat";
var type = Assembly.GetExecutingAssembly()
        .GetTypes()
        .FirstOrDefault(t => t.Name == tableName);

if(type != null)
    DbSet catContext = context.Set(type);

You also can get type from string using Full Assembly Qualified Name Type.GetType(' ... ')

If will be even easier if you can store configurations somehow in generic way and use the generic context.Set<T>() method.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...