//Method used for saving rates into the database
public bool saveRate(RateClass rate)
{
bool Successful = false;
CurrencyClass ccFrom = rate.getFrom();
CurrencyClass ccTo = rate.getTo();
//If entry does not exist insert it
if (checkForDuplicate(rate) == false)
{
try
{
string insert = "INSERT INTO CurrencyConverter ([CurFromLong], [CurFromShort], [CurToLong], [CurToShort], [Rate], [DateTime]) VALUES (@CurFromLong, @CurFromShort, @CurToLong, @CurToShort, @Rate, @DateTime);";
OleDbCommand cmd = new OleDbCommand(insert, MyConn);
cmd.Parameters.AddWithValue("@CurFromLong", ccFrom.getLongName());
cmd.Parameters.AddWithValue("@CurFromShort", ccFrom.getShortName());
cmd.Parameters.AddWithValue("@CurToLong", ccTo.getLongName());
cmd.Parameters.AddWithValue("@CurToShort", ccTo.getShortName());
cmd.Parameters.AddWithValue("@Rate", rate.getRate().ToString());
cmd.Parameters.AddWithValue("@DateTime", rate.getTimeDate().ToString());
cmd.ExecuteNonQuery();
Successful = true;
} //endtry
catch {}
} //endif
//if entry does exist, update it
else
{
try
{
string update = "UPDATE CurrencyConverter SET [Rate]=@Rate, [DateTime]=@DateTime WHERE CurFromShort LIKE '" + ccFrom.getShortName() + "' AND CurToShort LIKE '" + ccTo.getShortName() + "'";
OleDbCommand cmd = new OleDbCommand(update, MyConn);
cmd.Parameters.AddWithValue("@Rate", rate.getRate().ToString());
cmd.Parameters.AddWithValue("@DateTime", rate.getTimeDate().ToString());
cmd.ExecuteNonQuery();
Successful = true;
}//endtry
catch
{
//returns false
} //endcatch
} //endelse
return(Successful);
} //Saverate
} //OpenDatabaseConnection
//Checks to see if provided entry already exists in the Database
private bool checkForDuplicate(RateClass rate)
{
try
{
CurrencyClass ccFrom = rate.getFrom();
CurrencyClass ccTo = rate.getTo();
string CommandString = "Select * from CurrencyConverter where CurFromShort like '" + ccFrom.getShortName() + "' and CurToShort like '" + ccTo.getShortName() + "'";
OleDbCommand cmd = new OleDbCommand(CommandString, MyConn);
OleDbDataReader reader = cmd.ExecuteReader();
if (reader.HasRows)
{
return(true);
}
else
{
return(false);
}
}
catch
{
return(false);
}
} //checkForDuplicate