atamata questions

• Hide/display Telerik RadGrid columns on pre-render
• EntityFramework migration not removing 'IsRequired' from column
• Format string with MaskFormatter throws "Invalid character" exception
• EF Core throwing a concurrency error when adding entities to a list
• aggregate function to return true if value exists
• Can't edit files in Vscode
• Left Outer join and an additional where clause

atamata answers