A view in Oracle database is a virtual table. It does not contain any data, but is the result of taking data from one or more tables and performing operations such as arranging, grouping, calculation, etc., as a virtual table for users Query and operate. Views are widely used in Oracle database, but sometimes we need to delete a view. This article will introduce how to delete a view in Oracle database.
Things to note before deleting a view
Before deleting a view, you need to consider the following points:
How to delete a view
Oracle's DROP VIEW statement is used to delete an existing view. The syntax is as follows:
DROP VIEW view_name;
where view_name is the name of the view you want to delete.
For example, if we want to delete the view named EMP_SALARY, we can execute the following command:
DROP VIEW EMP_SALARY;
When the view is deleted, any query on it will return an error.
In addition, if the view is used by multiple users or programs at the same time, deleting the view may cause errors for these users or programs. Therefore, before deleting a view, make sure it is no longer in use.
Operations after deleting a view
Once a view is deleted, the following actions will occur:
Summary
View is a very important feature in Oracle database, which can help us simplify complex queries and analysis, improve query efficiency and data security. However, when using a view, we also need to pay attention to its deletion operation, ensure that the operation is correct and careful, and confirm that the view is no longer used before operating.
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