Add item for page 453

docs/errata/improvements.md

@@ -1,14 +1,11 @@
-**Improvements** (1 item)
+**Improvements** (2 items)
 
 If you have suggestions for improvements, then please [raise an issue in this repository](https://github.com/markjprice/cs11dotnet7/issues) or email me at markjprice (at) gmail.com.
 
-- [Print Book](#print-book)
-  - [Page 153 - Writing a function that returns a value](#page-153---writing-a-function-that-returns-a-value)
-- [Bonus Content](#bonus-content)
+- [Page 153 - Writing a function that returns a value](#page-153---writing-a-function-that-returns-a-value)
+- [Page 453 - Scaffolding models using an existing database](#page-453---scaffolding-models-using-an-existing-database)
 
-# Print Book
-
-## Page 153 - Writing a function that returns a value
+# Page 153 - Writing a function that returns a value
 
 At the end of this section there is a note box that explains that we could use the `C` format code to format the output as currency. If you are running on a computer in a culture that uses Euros then to show the Euro currency symbol you must enable UTF-8 encoding. 
 
@@ -18,6 +15,16 @@ Add the following statement near the top of the code file before doing any writi
 Console.OutputEncoding = System.Text.Encoding.UTF8;
 ```
 
-# Bonus Content 
+# Page 453 - Scaffolding models using an existing database
 
-None so far.
+In Step 2, I show text that must be entered as a single line at the command-line, as shown in the following command:
+```
+dotnet ef dbcontext scaffold "Filename=Northwind.db" Microsoft.
+EntityFrameworkCore.Sqlite --table Categories --table Products --output-
+dir AutoGenModels --namespace WorkingWithEFCore.AutoGen --data-
+annotations --context Northwind
+```
+
+I recommend that you copy and paste long commands like this from the eBook into a plain text editor like Notepad, and then make sure that the whole command is properly formatted as a single line, before you then copy and paste it to the command-line. 
+
+Copying and pasting directly from the ebook is likely to include newline characters and missing spaces and so on that break the command.