Updating multiple tables in mssql 100 online dating site australia
It's great to get the extra features, but it makes it harder to nail down exactly what you can and cannot do with views.Views have never in the past been able to contain parameters; however, as shown later in the chapter, user-defined functions can now be used like views, effectively allowing you to create parameterized views that return different results depending on the parameter values that get passed in each time the function is run.For example, the following view limits the result set by selecting only the employee first name, last name, and hire date columns from the Employees table, and it limits the rows returned to employees hired this year: One of the most powerful uses of views is for reporting. When the chain of ownership is broken, you need to grant users the same permissions on the underlying tables as you want them to have on the view, which nullifies the effectiveness of views as security mechanisms.A view can be used to wrap up complex queries containing subqueries, outer joins, and aggregation. Another problem you'll encounter with Access projects (ADPs) is that if you want users to be able to update data using a view, you also have to grant them permissions on the underlying tables.
These exercises allow you to try out your skills with the UPDATE statement.
To return the top 10 customers or the top 10% of customers, based on sales over the past year, SQL Server needs to sort customers by sales.
So, a view that returns the top 100% by sales would essentially be a sorted view.
Views give you a mechanism for presenting the same data to different users in different ways. As long as both the view and the Customers table are owned by dbo, the permissions granted on the view will take precedence over permissions removed from the Customers table. Because views allow you to restrict the rows and columns that are available, using them as a security tool is very convenient.
Columns and rows can be restricted, allowing users to focus on specific data that interests them. This also helps network performance because less data is traveling over the wire to client applications. For example, you could create two views on an Employees table, one with a sensitive salary column included that only managers had permissions on, and a second view with that column omitted for everyone else.Unlike stored procedures (which also support parameters), these parameterized functions can be updateable, as you'll see later in this chapter.The SQL-92 standard also mandates that views cannot be sorted with an values with a view; to support that, it also supports sorting. If you omit the WHERE clause, all records in the table will be updated!