How to load values from query to myClass properties using Dapper

Question

How to load values from query to myClass properties using Dapper

c# dapper orm

Question

I have a class called Students

    public class Students 
    {
     private string name ;
     private string age;
     private string adress;

    //Constructor 
    public Students (string name,string age,string adress)
    {
    this.name=name;
    this.age=age;
    this.adress=adress;
    }
  }

and a Query myQuery :

Select h.name 
b.age,
v.adress 
FROM Tb.Students h 
INNER JOIN db.tb_1 d 
ON h.id= d.id 
 INNER JOIN db.TB_2 v
 ON d.id = v.id

Now when I run this :

 Connection conn = new Connection();
        OracleConnection connection = conn.GetDBConnection();

 var studentsInfo= connection.Query<Students>(myQuery).ToList();

I noticed studentsInfo has results and row size is loaded but when I put the cursor on studentsInfo , the properties , Name , Age, Adress are empty

What I am missing ? How to assign the result of the query to my properties so I can use them like that :

foreach ( var student in studentsInfo )
{
 console.writeline(sutdent.age);
}

napi15

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Marc Gravell · Accepted Answer · 12/6/2017 9:50:41 PM

Not sure this will help, but it looks like what you have should work. I tend to work with SQL Server, but the ADO.NET layer is mostly the same, and I tried the following case:

using Dapper;
using System.Data.SqlClient;
using System.Linq;

public class Students
{
    private string name;
    private string age;
    private string adress;

    public Students(string name, string age, string adress)
    {
        this.name = name;
        this.age = age;
        this.adress = adress;
    }
    public override string ToString() => $"{name}, {age}, {adress}";
}
static class P
{
    static void Main()
    {
        using (var connection = new SqlConnection("Data Source=.;Initial Catalog=master;Integrated Security=SSPI;"))
        {
            const string myQuery = "select 'fred' as [name], '27' as [age], 'somewhere' as [adress]";
            var studentsInfo = connection.Query<Students>(myQuery).ToList();
            foreach(var student in studentsInfo)
            {
                System.Console.WriteLine(student);
            }
        }
    }
}

It worked fine, outputting:

fred, 27, somewhere

So my main thoughts would be: does the query output what you think it outputs? Is the data what you think it is? Also: are you sure that age is a string?

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