从宏更新Access数据库

Question

Dim deliveryCode As String
Set dbname = CurrentDb()
deliveryCode = 334
dbname.Execute "Update orderEntry set delivery= " & deliveryCode & " where ID=1"

当deliveryCode值为整数时，以上代码可以正常工作，但是将deliveryCode值更改为字符串后，出现错误：

Run time error 3061 Too few parameters Expected 1