Invariably, either while building a new database or while maintaining old ones, you will find that the business needs a change or that you've made a mistake. Either way, you will need to modify the tables that you've created. Change is inevitable, and luckily, SQL Server takes that into account, providing you with mechanisms to modify structures after you've created them.
Important WarningOne of the fundamental concepts of databases is that the data is stored. You can't simply throw data away when you need to make a change to a table. There are two levels of changes you can make to a table. The first is a change that won't affect the data in the table. These are simple changes and we'll cover them in this blog post. The second level of change is a change that can affect data in the table. This is a much more complicated change requiring multiple steps to protect the data in the table. This will be covered in later blog posts after you've learned more about how to work with data and structures.
No comments:
Post a Comment