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c#sqlconnection

SQL ERROR System.Collections.Generic.List`1[Dapper.SqlMapper+DapperRow]

I would like my code to return a value but it returns me:

System.Collections.Generic.List`1[Dapper.SqlMapper+DapperRow]

I can't solve and make a right output process.

public static string Test()
{
    using (IDbConnection cnn = new SQLiteConnection(LoadConnectionString()))
    {
        var vartest = cnn.Query("select grado from utenti where id='10'");
        //var result = output.ToDictionary(row => (string)row.Grado, row => (string)row.Nome ) ; (commento)
        //Console.WriteLine(vartest);

        cnn.Close();
        return vartest.ToString();
    }
}
Solution

  • Query and Query<T> return multiple rows; Query is for dynamic rows; Query<T> is for typed rows. There are QueryFirst[<T>] and QuerySingle[<T>] for single rows.

    If you're after a single value of a known type, then perhaps:

    var vartest = cnn.QuerySingle<string>("select grado from utenti where id='10'");