Insert into database through loop

I've created a procedure named UpsertDailyChange which inserts or updates data to these tables. Here is the complete create database listing.

CREATE DATABASE Forex;
GO
USE Forex;
GO

CREATE TABLE Currency
(
    CurrencyID INT IDENTITY(1, 1) PRIMARY KEY,
    Symbol VARCHAR(10) NOT NULL,
    Description VARCHAR(200),
);
   
CREATE TABLE DailyChange
(
    DailyChangeID INT IDENTITY(1, 1) PRIMARY KEY,
    CurrencyID INT FOREIGN KEY REFERENCES Currency(CurrencyID),
    Date DATE NOT NULL,
    Opening MONEY NOT NULL,
    Low MONEY NOT NULL,
    High MONEY NOT NULL,
    Closing MONEY NOT NULL
);
GO

CREATE PROCEDURE UpsertDailyChange
    @currencySymbol VARCHAR(10),
    @currencyDescrption VARCHAR(200),
    @date DATE,
    @opening MONEY,
    @low MONEY,
    @high MONEY,
    @closing MONEY
AS
BEGIN
    DECLARE @currencyID INT;
    DECLARE @dailyChangeID INT;
   
    SELECT @currencyID = CurrencyID FROM Currency WHERE Symbol=@currencySymbol;
   
    IF @currencyID IS NULL
        BEGIN
            INSERT INTO Currency(Symbol, Description) VALUES (@currencySymbol, @currencyDescrption);
            SELECT @currencyID=@@IDENTITY;
        END
       
    SELECT @dailyChangeID = DailyChangeID FROM DailyChange WHERE CurrencyID=@currencyID AND Date=@date;
   
    IF (@dailyChangeID IS NULL)
        INSERT INTO DailyChange(CurrencyID, Date, Opening, Low, High, Closing) VALUES (@currencyID, @date, @opening, @low, @high, @closing);
    ELSE
        UPDATE DailyChange SET Opening=@opening, Low=@low, High=@high, Closing=@closing WHERE DailyChangeID=@dailyChangeID;
       
END;
GO

The procedure accepts currency symbol and its description and then all information about the daily change for that symbol. If currency does not exist in the Currency table, it will be inserted. If daily change for given currency and date does not exist it will be inserted. Otherwise, if daily change does exist, then only opening/closing and low/high fields will be updated in that row (therefore the name UpsertDailyChange).

This procedure can be called from SQL Server Management Studio for testing purposes:
EXEC UpsertDailyChange 'RSD', 'Serbian Dinar', {d '2011-07-14'}, 1, 2, 9, 6;
EXEC UpsertDailyChange 'RSD', 'Serbian Dinar', {d '2011-07-15'}, 6, 4, 5, 4;
EXEC UpsertDailyChange 'RSD', 'Serbian Dinar', {d '2011-07-16'}, 4, 1, 5, 3;
EXEC UpsertDailyChange 'RSD', 'Serbian Dinar', {d '2011-07-15'}, 6, 4, 8, 4;

These statements are inserting daily changes for period July 14-16. Last statement updates July 15 record. Resulting data are collected with query:
SELECT * FROM DailyChange ORDER BY Date;

And here are the data:
DailyChangeID        CurrencyID        Date        Opening        Low        High        Closing
1    1    2011-07-14    1.00    2.00    9.00    6.00
2    1    2011-07-15    6.00    4.00    8.00    4.00
3    1    2011-07-16    4.00    1.00    5.00    3.00

Now, do you need help to call this procedure from the C# code?

Zoran