Question

I’m querying a database with SQLite. I’m trying to get data from this database, save it in an array, then return to the controller. I need to present this data using a foreach loop in my view.

string sql = "select * from Tasks Where UserId = " + userId.ToString();
using (SQLiteConnection conn = new SQLiteConnection(connString))    
{
    SQLiteCommand cmd = new SQLiteCommand(sql, conn);
    conn.Open();
    using (SQLiteDataReader rdr = cmd.ExecuteReader()) 
    {
        int i = 0;
        while (rdr.Read()) 
        {
            //here is what i would do in PHP
            $array[$i]['name'] = $rdr[i]["name"];
            $array[$i]['key']  $rdr[$i]["key"];
        }
    }
}

return array;

Answer 1

Firstly, learn to use parameterised queries not string concatenation as this will help prevent SQL injection attacks.

string sql = "select * from Tasks Where UserId = @userId";

Also, if you create a class to represent a record in your Tasks table then you can build instances of this object and return them in a list which will make using the code easier since instead of having untyped arrays, you will have an object with properties (in your view you can do foreach (var task in Model) where Model is a List<Task>.

public class Task
{
    public int Id { get; set; }
    public string Name { get; set; }
    public string Key { get; set; }
}

var tasks = new List<Task>(); // create a list to populate with tasks

using (var connection = new SQLiteConnection(connString))    
{
    var command = new SQLiteCommand(sql, conn);
    command.Parameters.Add("@userId", userId); // only do .ToString on userId if the column is a string.

    connection.Open();
    using (var reader = cmd.ExecuteReader()) 
    {
        while (reader.Read()) 
        {
            var task = new Task();
            task.Id = (int)reader["id"]; // the name of the column in the reader will match the column in the Tasks table.
            task.Name = (string)reader["name"];
            task.Key = (string)reader["key"];

            tasks.Add(task);
        }
    }
}

return tasks;

Instead of writing all the query logic and creating objects, you can use frameworks called Object Relational Mappers (ORM) to do this for you. There are a number of them around, some more simple than others. A MicroORM may suit your purposes, they are simple and easy to use (I have built one called MicroLite but there are others such as dapper or PetaPoco. If you want something more powerful, NHibernate and Entity Framework are popular choices.