Question

I’m creating a search engine for my asp page.There are 15 pieces filtering options like Price,Date,Name etc.
Also,The use of Filtering Options is optional.If the filtering options are left blank,search will be made.
I found a solution by using if and string.

string sorgu = "";
dbcommand cmd = CommandClassım.YeniCommand();
sorgu += "Select * From Urunler Where ";
if(UrunAdi.Text != string.Empty)
{
sorgu += "UrunAdi = @UrunAdi";
dbparameters prm = cmd.createparameter();
prm.Parametername = "@UrunAdi";
prm.Value = UrunAdi.Text;
prm.DbType = DbType.String;
cmd.Parameters.Add(prm);
}
cmd.CommandText = sorgu; 

it’s running upper code without problem.However,I want to using a parameter to filter dynamic.
So,the user choose those categories through checkbox inside search engine.

When I try to run below code,I got the following error.

Must declare the scalar variable "@cat0". 

Code:

string sorgu = "";
DbCommand cmd = CommandClassım.YeniCommand();
sorgu += "Select * From Urunler Where ";
DbParameter prm = cmd.CreateParameter;
for(int i = 0; i < Category.Length; i++)
{
sorgu += "Kategori = @cat" + i.ToString();
prm.ParameterName = "@cat" + i.ToString();
prm.Value = Category.Value;
prm.DbType = DbType.String;
cmd.Parameters.Add(prm);
}
cmd.CommandText = sorgu;  

Answer 1

Just a hunch, but could it be that you’re not providing the indexer for Category?

prm.Value = Category.Value;

I would think it should be:

prm.Value = Category[i].Value;