execute custom sql with entity framework?

Here's another dimension and easier approach. Get SQL Connection using your Entity Framework Context:

var connection = (System.Data.SqlClient.SqlConnection) _db.Database.Connection;

if (connection != null && connection.State == ConnectionState.Closed)
{
    connection.Open();
}

var dt = new DataTable();

using (var com = new System.Data.SqlClient.SqlDataAdapter("Select * from Table", connection))
{
    com.Fill(dt);
}

And we can use DataAdapter or any other classic method to execute queries using the EF connection.

This will be very useful when we do something dynamically and when we can't map to a Entity. We can get things in a DataTable for example.

The above Syntax is for EF 5.0.

If your goal is to return ADO.NET structures (DataTable or DataSet), then just use classic ADO.NET. You'll find it easier than trying to bind data to an Entity set and then populating a DataTable or DataSet yourself.

However, if you're really and truly interested running a custom query through EntityFramework, take a look at ExecuteQuery. It allows you to execute a SQL Query and maps the result back to entities in your model. It would then be an exercise on your part to take the IEnumerable result and map it to a DataTable or DataSet. Hence my original answer of "just do it with good ol' fashioned ADO.NET methods."

For Entity Framework 5 use

context.Database.SqlQuery

---

And For Entity Framework 4 use the following code

context.ExecuteStoreQuery

---

 public string BuyerSequenceNumberMax(int buyerId)
    {
        string sequenceMaxQuery = "SELECT TOP(1) btitosal.BuyerSequenceNumber FROM BuyerTakenItemToSale btitosal " +
                                  "WHERE btitosal.BuyerID =  " + buyerId +
                                  "ORDER BY  CONVERT(INT,SUBSTRING(btitosal.BuyerSequenceNumber,7, LEN(btitosal.BuyerSequenceNumber))) DESC";

        var sequenceQueryResult = context.Database.SqlQuery<string>(sequenceMaxQuery).FirstOrDefault();

        string buyerSequenceNumber = string.Empty;

        if (sequenceQueryResult != null)
        {
            buyerSequenceNumber = sequenceQueryResult.ToString();
        }

        return buyerSequenceNumber;
    }

For Return a List use the following Code

 public List<PanelSerialList> PanelSerialByLocationAndStock(string locationCode, byte storeLocation, string itemCategory, string itemCapacity, byte agreementType, string packageCode)
 {
       string panelSerialByLocationAndStockQuery = "SELECT isws.ItemSerialNo,  im.ItemModel " +
        "FROM Inv_ItemMaster im   " +
        "INNER JOIN  " +
        "Inv_ItemStockWithSerialNoByLocation isws  " +
        "   ON im.ItemCode = isws.ItemCode   " +
        "       WHERE isws.LocationCode = '" + locationCode + "' AND  " +
        "   isws.StoreLocation = " + storeLocation + " AND  " +
        "   isws.IsAvailableInStore = 1 AND " +
        "   im.ItemCapacity = '" + itemCapacity + "' AND " +
        "   isws.ItemSerialNo NOT IN ( " +
        "           Select sp.PanelSerialNo From Special_SpecialPackagePriceForResale sp  " +
        "           Where sp.PackageCode = '" + packageCode + "' )";



    context.Database.SqlQuery<PanelSerialList>(panelSerialByLocationAndStockQuery).ToList();


}