Beginning Microsoft SQL Server 2008 ... - S3 Tech Training

Chapter 10: Views
NULL values will need to appear in the view in order for INSERTs to be allowed through the view. The
only way to get around this is — you guessed it — with an INSTEAD OF trigger.
Limit What’s Inserted into Views — WITH CHECK OPTION
The WITH CHECK OPTION is one of those obscure features in SQL Server. The rules are simple — in order
to update or insert data using the view, the resulting row must qualify to appear in the view results.
Restated, the inserted or updated row must meet any WHERE criterion that’s used in the SELECT statement
that underlies your view.
Try It Out WITH CHECK OPTION
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To illustrate the WITH CHECK OPTION, let’s continue working with the AdventureWorks2008 database,
and create a view to show only Portland, Oregon area addresses. We have only limited fields to work
with in our Address table, so we’re going to have to make use of the PostalCode in order to figure out
where the area address is. We’ve been provided enough information to allow us to filter based on
PostalCodes that start with 970, 971, and 972 for the Portland side of the border, and 98660 to 98699 for
the Vancouver, Washington side, so we apply it in a view:
CREATE VIEW PortlandAreaAddresses_vw
AS
SELECT AddressID,
AddressLine1,
City,
StateProvinceID,
PostalCode,
ModifiedDate
FROM Person.Address
WHERE PostalCode LIKE ‘970%’
OR PostalCode LIKE ‘971%’
OR PostalCode LIKE ‘972%’
OR PostalCode LIKE ‘986[6-9]%’
WITH CHECK OPTION;
Run a SELECT * against this view, and you return about 792 rows:
AddressID AddressLine1 City StProvID PostalCode ModifiedDate
---------- -------------------- ------------ -------- ---------- ------------
22 636 Vine Hill Way Portland 58 97205 2001-06-24
312 1286 Cincerto Circle Lake Oswego 58 97034 2002-01-23
322 1 Mt. Dell Drive Portland 58 97205 2002-01-24
…
…
29792 5186 Oeffler Ln. Beaverton 58 97005 2003-03-20
29822 2613 West I St. Beaverton 58 97005 2003-12-25
29856 1132 Plymouth Dr. Lake Oswego 58 97034 2004-04-07
(792 row(s) affected)