Summary: in this tutorial, we will show you how to create an updateable view and update data in the underlying table through the view.
In MySQL, views are not only read-only but also updateable. However in order to create an updateable view, the SELECT statement that defines the view has to follow several following rules:
The
SELECT
statement must only refer to one database table.The
SELECT
statement must not use GROUP BY or HAVING clause.The
SELECT
statement must not use DISTINCT in the column list of theSELECT
clause.The
SELECT
statement must not refer to read-only views.The
SELECT
statement must not contain any expression (aggregates, functions, computed columns…)
When you create updateable views, make sure that you follow the rules above.
Example of creating updateable view
Let’s practice with an example of creating an updateable view.
First, we create a view named officeInfo
against the offices
table. The view refers to three columns of the offices
table: officeCode
, phone
and city
.
CREATE VIEW officeInfo AS SELECT officeCode, phone, city FROM offices
Next, we can query data from the officeInfo
view using the SELECT
statement.
SELECT * FROM officeInfo
Then, we can change the phone number of the office with Finally, to see the change, we can select the data from the In this tutorial, we have shown you how to create an updateable view and how to update data in the underlying table through the view. 原文链接:http://outofmemory.cn/mysql/view/create-sql-updatable-viewsofficeCode
4 through the officeInfo
view by using the officeInfo
view by executing following query:SELECT * FROM officeInfo WHERE officeCode = 4
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