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Pivot Sql Table column to a list c#

Posted on 2010-08-13
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Last Modified: 2013-12-17

Hi,

I have a question about how to pivot a sql table column into a list of objects.

Assume I have a product table with columns:

product id    location    price
    1                 x             $10
    1                 y             $12
    1                 z             $14

I created a (location, price) class and a product class as:

public class priceLocation
{
      public string location;
      public decimal price;
}

and
public class product
{
      public int productid;
      public list<priceLocation> priceLocations;
}
public list<object> locationprice

How can I load the above sql data to these classes?

Thanks
0
Comment
Question by:sofux
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5 Comments
 
LVL 5

Expert Comment

by:JayFromPep
ID: 33432685
I think that LINQ would be the way to go.

Check this article....

http://www.c-sharpcorner.com/UploadFile/scottlysle/L2SinCS06022008035847AM/L2SinCS.aspx
0
 

Author Comment

by:sofux
ID: 33433790
I am not sure how it helps.

Let me clarify little bit:

product id    location    price
    1                 x             $10
    1                 y             $12
    1                 z             $14
    2                 x             $15
    2                 y             $17
    2                 z             $13

need to convert this table to create a product list. If I had to do it manually, it would look like this:

list<product> Products = new list<product>
    { new Product{productid = 1, new List<priceLocation>{new priceLocation{location = x, price =10},
                                                                                            new priceLocation{location = x, price =12},
                                                                                            new priceLocation{location = x, price =14}}},
       new Product{productid = 2, new List<priceLocation>{new priceLocation{location = x, price =15},
                                                                                            new priceLocation{location = x, price =17},
                                                                                            new priceLocation{location = x, price =13}}}};

I am familiar with linq but not sure if this can be accomplished with linq.
Thanks.


0
 
LVL 2

Accepted Solution

by:
Algol36 earned 1500 total points
ID: 33436629
       public class priceLocation
        {
              public string location;
              public decimal price;
        }

        public class product
        {
              public int productid;
              public List<priceLocation> priceLocations;
        }
        public List<product> locationprice;

        public void Run()
        {
            //create example datatable
            DataTable table = new DataTable();
            table.Columns.Add("productId", typeof(int));
            table.Columns.Add("location", typeof(string));
            table.Columns.Add("price", typeof(decimal));
            table.Rows.Add(1, "x", "10");
            table.Rows.Add(1, "y", "20");
            table.Rows.Add(1, "z", "15");
            table.Rows.Add(2, "x", "10");
            //using linq to extract data into classes
            var query = from prod in table.AsEnumerable()
                        group prod by prod["productId"]
                            into grp
                            select new product
                            {
                                productid = (int)grp.Key,
                                priceLocations = grp.Select<DataRow, priceLocation>(
                                    l => new priceLocation() {
                                        location = (string)l["location"],
                                        price = (decimal)l["price"]
                                        }
                                    ).ToList()
                            };

            locationprice = query.Cast<product>().ToList<product>();
        }
0
 

Author Comment

by:sofux
ID: 33441872
Thanks.

Need to small adjustments but overall it works.

This part of the code didn't work:

grp.Select<DataRow, priceLocation>(
                                    l => new priceLocation() {
                                        location = (string)l["location"],
                                        price = (decimal)l["price"]
                                        }

so I replaced this with:

grp.Select( l => new priceLocation() {
                                        location = l.location,
                                        price = l.price
                                        }

0
 

Author Closing Comment

by:sofux
ID: 33441878
Provided very good direction but further improvements required on my side.
0

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