A Beginners' Guide to Blazor WebAssembly - Data validation and preventing duplicates

Data validation in a Blazor WebAssembly application using Data Annotations, plus how to prevent duplicate records getting added to the database. Useful links: Video script & code: https://blazorcode.uk/countriesandcitieswasm/data-validation/ Data Annotations examples: https://www.codemag.com/Article/2301031/The-Rich-Set-of-Data-Annotation-and-Validation-Attributes-in-.NET A Practical Guide to Dapper: https://www.red-gate.com/simple-talk/development/dotnet-development/a-practical-guide-to-dapper/ StackOverflow – Carriage return behaviour: https://stackoverflow.com/questions/61167239/blazor-preventdefault-on-submit-form