What is view in PL SQL?
What is view in PL SQL?
In SQL, a view is a virtual table based on the result-set of an SQL statement. A view contains rows and columns, just like a real table. The fields in a view are fields from one or more real tables in the database.
Why do we use view in PL SQL?
The benefits of using views include reducing the complexity of SQL statements, hiding the NAME and OWNER of the base table, and only sharing specific table rows with other users. View details can be queried from within the data dictionary, by using ALL_VIEWS, USER_VIEWS, or DBA_VIEWS.
What is an Oracle view?
An Oracle VIEW, in essence, is a virtual table that does not physically exist. Rather, it is created by a query joining one or more tables.
Why do we use view in Oracle?
A view is a virtual table because you can use it like a table in your SQL queries. To be precise, a view only behaves like a table. And it is just a named query stored in the database. When you query data from a view, Oracle uses this stored query to retrieve the data from the underlying tables.
What is view in Oracle and types?
In Oracle, view is a virtual table that does not physically exist. It is stored in Oracle data dictionary and do not store any data. It can be executed when called. A view is created by a query joining one or more tables.
How many types of views are there?
There are total four types of views, based on the way in which the view is implemented and the methods that are permitted for accessing the view data. They are – Database Views, Projection Views, Maintenance Views, and Helps Views,.
Why do we use view?
Views are used for security purposes because they provide encapsulation of the name of the table. Data is in the virtual table, not stored permanently. Views display only selected data. We can also use Sql Join s in the Select statement in deriving the data for the view.
What is the purpose of a view?
Views can provide advantages over tables: Views can represent a subset of the data contained in a table. Consequently, a view can limit the degree of exposure of the underlying tables to the outer world: a given user may have permission to query the view, while denied access to the rest of the base table.
How do I create a view in SQL?
The CREATE VIEW syntax. To create a view in SQL Server, use the CREATE VIEW statement, which is shown in the following syntax: Syntax for creating a view in SQL Server. Not surprisingly, you begin with the CREATE VIEW clause, providing the name and, optionally, the schema where you want to define the view.
How do you use view in SQL?
Locate the query in Object Explorer and double-click it to run the query. Pull down the View menu in the upper left corner of the ribbon. Select SQL view to display the SQL statement corresponding to the query. Make any edits you wish to the SQL statement in the query tab.
What are the types of views in SQL?
In Sql Server we have two types of views. System Defined Views System defined Views are predefined Views that already exist in the Master database of Sql Server. These are also used as template Views for all newly created databases. User Defined Views These types of view are defined by users. We have two types of user defined views.
How to create view in SQL Server?
ENCRYPTION – Using this attribute prevents the view from being published as part of SQL Server replication
