https://learn.microsoft.com/en-us/dotnet/api/system.data.common.dbcolumn.datatypename?view=netframework-4.8.1&viewFallbackFrom=netcore-3.1
DbColumn.DataTypeName Property (System.Data.Common) | Microsoft Learn
Gets the name of the data type; otherwise, null if no value is set. Can be set to either the data type name or null when overridden in a derived class.
property systemdatacommonmicrosoftlearn