Dapper中的地图数据库和模型

Question

My database:

uId | uName | uAge | uAddress

Model:

public int Id {get; set;}
public int Name {get; set;}
public int Age {get; set;}
public int Address {get; set;}

Query:

public User GetUserById(int userId)
{
   using (SqlConnection con = new SqlConnection(_connectionString.Value.ConnectionString))
   {
       var param = new DynamicParameters();
       param.Add("@userID", userId);
       return con.Query("GetuserDetails", param, null, true, 0, System.Data.CommandType.StoredProcedure).SingleOrDefault();
   }
}

Is there any way that I can map these?

On the other side I tried to change my property as per DB and used JsonProperty in the annotation,

[JsonProperty("Name")]
public string uName { get; set; }

But after consuming the data in the client and converting back to User object will it throws null again. I can't change the column name in the DB as that will be the standard and I wanted the property name to be clean (Name, Age) too.

Any help? Am I wrong somewhere?

Answer 1

What you have to do is create a constructor with the names of the columns and the correct types. Assuming you are on SQL-Server, it would be the following:

public class User
{
   public User(int uId, string uName, int uAge, string uAddress)
   {
      Id = uId;
      Name = uName;
      Age = uAge;
      Address = uAddress;
   }
}

Now you can change the sql-query invocation to this:

return con.Query<User>("GetuserDetails", param, null, true, 0, System.Data.CommandType.StoredProcedure).SingleOrDefault();

Now Dapper is able to map them to your class because it finds a constructor matching to the column- names and types. If you need an empty constructor as well, just add one without any parameters.

Answer 2

Why don't you use ColumnAttributeTypeMapper ?

[Column("uId")]
public int Id {get; set;}
[Column("uName")]
public int Name {get; set;}
[Column("uAge")]
public int Age {get; set;}
[Column("uAddress")]
public int Address {get; set;}