Sql query syntax in C#?

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I'm trying to run a query on a table but keep getting the error:

The parameterized query '(@TourName char(8000))UPDATE ToursTbl SET Availability = (Availa' expects the parameter '@TourName', which was not supplied.

I guessing its to do with how I've provided the @TourName parameter. Heres my code Any help??

for (int i = 0; i < bookedToursArray.Length; i++)
           {
               //command to update the number of available tours in the tours table
               SqlCommand cmd2 = new SqlCommand();
               cmd2.CommandText = "UPDATE ToursTbl SET Availability = (Availability-1) WHERE TourName = '@TourName'";
               cmd2.Parameters.Add("@TourName", SqlDbType.Char).Value = bookedToursArray[i];

               cmd2.Connection = conn;

               conn.Open();

               cmd2.ExecuteNonQuery();

               conn.Close();
           }

What I have tried:

The problem seems to be my syntax

Posted 20-May-17 9:22am

Gerald McAuley

Updated 20-May-17 9:43am

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[no name] 20-May-17 15:37pm

"The problem seems to be my syntax", you seem to be correct. Get rid of the single quotes and use AddWithValue instead.

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CHill60 · Accepted Answer · 2017-05-20T09:43:00

See the line

C#

cmd2.CommandText = "UPDATE ToursTbl SET Availability = (Availability-1) WHERE TourName = '@TourName'";

When using parameterized queries the single-quotes are added for you. That line should be

C#

cmd2.CommandText = "UPDATE ToursTbl SET Availability = (Availability-1) WHERE TourName = @TourName";

Your next problem is with

C#

cmd2.Parameters.Add("@TourName", SqlDbType.Char).Value = bookedToursArray[i];

Don't use Add - change it to

C#

cmd2.Parameters.AddWithValue("@TourName",bookedToursArray[i]);