For a .NET backend mobile service, the data model is defined in the Visual Studio project by using Code First in the Entity Framework. Changes are made to a published data model using Code First Migrations. For more information, see How to make data model changes to a .NET backend mobile service.
Once a column is created, its data type cannot be changed by Mobile Services. Insert or update operations fail when the type of a property in the JSON object cannot be converted to the type of the equivalent column in the table.
To delete columns, click the column and then click Delete.
When you delete a column, all data stored in that column is deleted. You should not delete system columns, which have a "__" prefix.
You can improve the performance of queries by having a well-defined index on the table. The table index should include any columns that are regularly used in queries, especially for filtering and sorting. To add a column to the index, select the column and click Set as Index.