Question

When I attempt to execute the following non query sql command in my application I always get the error message –

Must declare the scalar variable ‘@RateID’

I’m a bit at a loss as to why I receive this error. Here is my code:

string sqlText = "INSERT INTO tblRates (RateID, IPName, RateName, Rate, DateFrom, DateTo, Active) " +
                 "VALUES (@RateID, @IPName, @RateName, @Rate, @DateFrom, @DateTo, @Active);";

SqlCommand sqlCom = new SqlCommand(sqlText);
sqlCom.Parameters.Add("@RateID", SqlDbType.Int);
sqlCom.Parameters.Add("@IPName", SqlDbType.Text);
sqlCom.Parameters.Add("@RateName", SqlDbType.Text);
sqlCom.Parameters.Add("@Rate", SqlDbType.Decimal);
sqlCom.Parameters.Add("@DateFrom", SqlDbType.Date);
sqlCom.Parameters.Add("@DateTo", SqlDbType.Date);
sqlCom.Parameters.Add("@Active", SqlDbType.Bit);

this._rateID = NextID();

sqlCom.Parameters["@RateID"].Value = this._rateID;

if (this._ipName == "All")
{
   sqlCom.Parameters["@IPName"].Value = DBNull.Value;
}
else
{
   sqlCom.Parameters["@IPName"].Value = this._ipName;
}

sqlCom.Parameters["@RateName"].Value = this._rateName;
sqlCom.Parameters["@Rate"].Value = this._rate;
sqlCom.Parameters["@DateFrom"].Value = this._dateFrom;
sqlCom.Parameters["@DateTo"].Value = this._dateTo;

this._active = true;
sqlCom.Parameters["@Active"].Value = this._active;

cSqlQuery cQ = new cSqlQuery(sqlText, "non query");

When I step through line by line, I see the parameter @RateID is successfully added to the sqlCommand object, the method NextID correctly returns an integer value which is accepted as the Value of the @RateID parameter, but when I execute non query on the SqlCommand I get the aforementioned error.

Any help much be much appreciated.

Answer 1

You’re setting up the sqlCom object – and the code looks fine.

But then: it seems you’re just executing the SQL command here:

cSqlQuery cQ = new cSqlQuery(sqlText, "non query");

not using all that setup code you had before! Why?

The parameters and all are contained in the sqlCom object – but your cSqlQuery doesn’t seem to actually look at that object – just the SQL statement itself…

What happens if you use this line instead:

sqlCom.ExecuteNonQuery();

Does this work without exception?