Quick Help: converting SQL to LINQ - sql

Question

How do you convert this SQL to LINQ?
I'm reading it now, but just putting this out there in case I can't do it.
SqlConnection connection = new SqlConnection
{
ConnectionString = ConfigurationManager.ConnectionStrings["HBOS"].ConnectionString
};
connection.Open();
foreach (ExchangeRateData x in exchangeRateDatas.ExchangeRateDataList)
{
SqlCommand cmd = new SqlCommand("UPDATE dbo.CurrencyExchange " +
"SET Rate = '" + x.Rate + "', DateTimeStamp = CAST('" + x.TimeStamp +
"' AS DATETIME), CreatedBy = '" + x.CreatedBy + "', RateInv = '" +
x.RateInv + "' " +
"WHERE Currency = '" + x.ToCurrency + "';", connection);
// Sql query and connection
cmd.ExecuteNonQuery();
}
connection.Close();

Answer 1

Create a dbcontext first
then
CurrencyExchange CurrencyExchangeObject = context.CurrencyExchange
.Where(a => a.Currency = x.ToCurrency)
.FirstOrDefault();
after that you can simple assign the values
like
CurrencyExchangeObject.Rate = x.Rate;
CurrencyExchangeObject.DateTimeStamp = Convert.ToDateTime(x.TimeStamp);
and then simply say
context.SaveChanges();

Answer 2

Sounds like your boss is looking for a LINQ to SQL implementation. Unfortunately, your question does not have a quick answer because adding this functionality requires a lot more than just "converting a query to LINQ", as there are a number of things needed to get your environment set up to support it.
You may want to start with some basic Googling of the topic:
First couple results:
http://weblogs.asp.net/scottgu/archive/2007/05/19/using-linq-to-sql-part-1.aspx
http://msdn.microsoft.com/en-us/library/bb386976(v=vs.110).aspx
LINQ to SQL has a more widely-used cousin called Entity Framework, which is not dependent upon SQL Server. You may want to consider that as well.