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Extract datarow to c # object

I have a class item that represents an item in a list. I have a function that calls a stored procedure that returns a datatable, and I need to convert the datatable to an Array of elements. That's what I'm doing:

public class Item
{
    private string _ItemIdDataName = "item_id";
    private string _ItemNameDataName = "item_name";
    private string _PriceDataName = "price";

    public long ItemId { get; set; }
    public string ItemName { get; set; }
    public float Price { get; set; }

    private Item(DataRow row)
    {
        if (row != null)
        {
            ItemId = long.Parse(row[_ItemIdDataName].ToString());
            ItemName = row[_ItemNameDataName].ToString();
            Price = float.Parse(row[_PriceDataName].ToString());
        }
    }

    public Item[] load()
    {
        DataTable dt=DBHandler.GetItems();//Stored procedure that returns DataTable 
        Item[] items = new Item[dt.Rows.Count];
        for (int i = 0; i < dt.Rows.Count; i++)
        {
            items[i] = new Item(dt.Rows[i]);
        }
        return items;
    }
}

Am I doing it right? How can I improve this?

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4 answers

, , , . , DataTable, . , , ( , ):

public static class DataTableExtensions
{
    public static IList<T> ToList<T>(this DataTable table) where T : new()
    {
        IList<PropertyInfo> properties = typeof(T).GetProperties().ToList();
        IList<T> result = new List<T>();

        foreach (var row in table.Rows)
        {
            var item = CreateItemFromRow<T>((DataRow)row, properties);
            result.Add(item);
        }

        return result;
    }

    public static IList<T> ToList<T>(this DataTable table, Dictionary<string, string> mappings) where T : new()
    {
        IList<PropertyInfo> properties = typeof(T).GetProperties().ToList();
        IList<T> result = new List<T>();

        foreach (var row in table.Rows)
        {
            var item = CreateItemFromRow<T>((DataRow)row, properties, mappings);
            result.Add(item);
        }

        return result;
    }

    private static T CreateItemFromRow<T>(DataRow row, IList<PropertyInfo> properties) where T : new()
    {
        T item = new T();
        foreach (var property in properties)
        {
            property.SetValue(item, row[property.Name], null);
        }
        return item;
    }

    private static T CreateItemFromRow<T>(DataRow row, IList<PropertyInfo> properties, Dictionary<string, string> mappings) where T : new()
    {
        T item = new T();
        foreach (var property in properties)
        {
            if(mappings.ContainsKey(property.Name))
                property.SetValue(item, row[mappings[property.Name]], null);
        }
        return item;
    }
}


var items = dt.ToList<Item>();


var mappings = new Dictionary<string,string>();
mappings.Add("ItemId", "item_id");
mappings.Add("ItemName ", "item_name");
mappings.Add("Price ", "price);
var items = dt.ToList<Item>(mappings);

: http://blog.tomasjansson.com/2010/11/convert-datatable-to-generic-list-extension

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. (Item) , . , , , , .

2: , , . , , , .

+23

, :

  • ToString . , /.

  • , SQL Server.

, :

ItemId = long.Parse(row[_ItemIdDataName].ToString());

:

 ItemId = row.Field<long?>(_ItemIdDataName) ?? value_if_null;

( System.Data.DatasetExtensions, )

+5

load() Item.

, - - .

So try
1. reorganize the private c'tor to say a helper class that just parses the DataRow and returns an instance of Item
2. and reorganize load()into another class that just uses the above helper method and returns an array of instances of the Item object

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