Improving the Class-to-Table Mapping

The dotnet-ef the command-line tool generates different codes for SQL Server and SQLite because they support different levels of functionality.

SQL Server and SQLite generated code

For example, SQL Server text columns can limit the number of characters. SQLite does not support this. So, dotnet-ef will generate validation attributes to ensure string properties are limited to a specified number of characters for SQL Server but not for SQLite, as shown in the following code:

Neither database provider will mark non-nullable string properties as required:

Improving entity model mapping and validation for SQLite

We will make some small changes to improve the entity model mapping and validation rules for SQLite. First, we will add a regular expression to validate that a CustomerId value is exactly five uppercase letters. Second, we will add string length requirements to validate that multiple properties throughout the entity models know the maximum length allowed for their text values:

Step 1: In Customer.cs, add a regular expression to validate its primary key value to only allow uppercase Western characters, as shown highlighted in the following code:

Step 2: Activate the code editor’s find and replace feature (in Visual Studio 2022, navigate to “Edit |Find” and “Replace | Quick Replace”), ...