Saving changes is not permitted. The changes that you have made require the following tables to be dropped and re-created.

ERROR:

“Saving changes is not permitted. The changes that you have made require the following tables to be dropped and re-created. You have either made changes to a table that can't be re-created or enabled the option Prevent saving changes that require the table to be re-created.”

This error happens because “Saving Changes is not permitted” when using SQL Server 2008 Management Studio to modify the structure of a table especially when SQL Server needs to drop and recreate a table to save the structural changes. It is always advised to make a structural change for a table using TSQL. However, it is a convenient option for database developers to use SQL Server Management Studio make such changes  as the  Prevent Saving Changes That Require Table Re-creation  option is enabled by default in SQL Server 2008 Management Studio.

Disable “Prevent saving changes that require the table re-creation”

1.    Open SQL Server 2008 Management Studio (SSMS). Click Tools menu and then click on Options... as shown in the snippet below.

2.    In the navigation pane of the Options window, expand Designers node and select Table and Database Designers option as shown in the below snippet. Under Table Options you need to uncheck “Prevent saving changes that require the table re-creation” option and click OK to save changes.

This option when enabled prevents users from making structural changes to table using SQL Server Management Studio especially when SQL Server needs to recreate the table to save changes. By default, this option is checked and you need to uncheck this option to allow users to make any structural change through SSMS that   require table recreation.

A table needs to be recreated whenever any of the below   changes are made to the table structure.

·         Insert a new column in the middle of the table.

·         Add a new column in the table.

·         Change the Allow Nulls setting of a column.

·         Modify the identity property of a column.

·         Reorder the columns within a table.

·        Modify the datatype of a column.

Once you have disabled “Prevent saving changes that require the table re-creation” option you can go ahead and save the changes to the Employee Table. This will create a Validation Warning dialog box as shown in the below snippet. The warning message will be “One or more existing columns have ANSI_PADDING 'off' and will be re-created with ANSI_PADDING 'on'”. Click “Yes” to save the changes.

Risks of Turing Off "Prevent Saving Changes that Require Table Re-creation" in SSMS

If you turn off this feature then you can avoid table recreation. However, if you have the Change Tracking feature of SQL Server 2008 enabled to track the table changes then the change tracking information will be lost completely whenever table is recreated. So, it is always advised to use this feature very carefully especially in a production environment.

Refer to http://www.sql-server-performance.com/faq/saving_changes_not_permitted_p1.aspx