Updating a view sql server
Therefore, a view can be considered a logical table. The SQL comprising the view is executed only when the view is accessed and views can be accessed by SQL in the same way that tables are by SQL.No physical structure is required of a view; it is a representation of data that is stored in other tables. When modifying data through a view (that is, using INSERT or UPDATE statements) certain limitations exist depending upon the type of view.This is a requirement of the relational model and is referred to as relational closure.A view is basically the relational model's way of turning a SELECT statement into a "table" that is accessible using SQL. They can consist of any combination of the following: Views are defined using SQL and are represented internally to SQL Server by a SELECT statement, not by stored data. If you omit the WHERE clause, all records in the table will be updated! The WHERE clause specifies which record(s) that should be updated.This causes the advantages of views to become muddled and misunderstood.As you read this article you will find that views are very useful when implemented wisely, but can be an administrative burden if implemented without planning.
There are 3 syntaxes for the UPDATE statement depending on whether you are performing a traditional update or updating one table with data from another table.For example, the UNION operator can not be used in a view and you cannot create a trigger on a view.All of the basic DDL statements can be used to create and manage views including CREATE, DROP, and ALTER.Additionally, inserting data is prohibited for the following types of views: It is also possible to insert or update data through a view such that the data is no longer accessible via that view, unless the WITH CHECK OPTION has been specified.Almost any SQL that can be issued natively can be coded into a view; there are exceptions, however.