必须声明标量变量

Question

Been looking over loads of other questions of this type but couldn't find any that helped me solved my problem.

Getting the error: Must declare the scalar variable "@SupplierID".

The code that's throwing the error:

 sqlProductFind = @"SELECT * from Product WHERE  SupplierID =  @SupplierID";
        conn = new SqlConnection(connstr);
        FindTheProducts = new SqlCommand(sqlProductFind, conn);
        FindTheProducts.Parameters.Add("@SupplierID", SqlDbType.Int);
        daProduct = new SqlDataAdapter(sqlProductFind, conn); //putting connection string in here
        //cmdProduct = new SqlCommandBuilder(daProduct);
        daProduct.FillSchema(dsProduct, SchemaType.Source, "Product");

Answer 1

I can see you creating a SqlCommand, setting the query and adding a parameter. But then you create a new SqlDataAdapter without using the SqlCommand and it's Parameter. You create the SqlDataAdapter with the query also, but you should have used the SqlCommand so the SqlDataAdapter will be instantiated with the SqlCommand as the SelectCommand.

daProduct = new SqlDataAdapter(FindTheProducts);

Also set the value of @SupplierID so you are actually going to filter on a supplierId.

int supplierId = 1; //Should be an input parameter
FindTheProducts.Parameters.Add("@SupplierID", supplierId);