HOW TO CREATE AN EXTENSION IN D365 ON TABLES. In Order to create an Extension on existing tables in D365 follow the below steps. 1 Create a new project. 2. Make sure the project has the models attached to it.i.e the tables model name. 3. right click on any table and select create extension. 4. 5. Th is will create an table with tablename.extension 6. you can add any fields over here i.e table level customization. 7. IF you want to add any method then you will have to create a class for the same 8. below is an example. [ExtensionOf(tableStr(CustTable))] final class CustTable_Extension { [SysClientCacheDataMethodAttribute(true)] //This attribute will cache your method. public static display Name myDisplayName(CustTable _this) { return _this.nameAlias() + "myDisplayName"; } } 9 You can add as many methods as you want over here . 1 The ex