Developers can use SQL Server “Denali”, MS SQL Server 2008 R2 and MS SQL Server 2005 Table Designer to delete a column. When developers delete a column, once they save the changes, the column and all the data it contains are deleted from the database. The only way to restore a deleted column is to close the table without saving changes. When developers want to delete a column, they should follow the next steps:
1. In Object Explorer, right-click the table to which they want to delete columns and choose Design (Modify in SP1 or earlier).
Table Designer opens.
2. Select the column they want to delete.
3. Right-click the column and choose Delete Column from the shortcut menu.
4. If the column participates in a relationship, a message prompts them to confirm the deletion of the selected columns and their relationships. Choose Yes.
If the column does participate in a check constraint, the database server will reject developers’ modification when they try to save their work. To delete a column that participates in a check constraint, they must first modify or remove the check constraint before they can delete the column.