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.

How do I view tables in PL SQL?

SELECT TABLE_NAME FROM USER_TABLES will provide you with listing of tables in a particular schema. SELECT TABLE_NAME, OWNER FROM ALL_TABLES will provide you with listing of all tables for all schemas in the DB for which you have at least select privilege.

How do I open a view in PL SQL Developer?

I found that I can press SHIFT+F4 for a view in SQL Developer and get the script of the view in Details Tab.

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.

How do I create a view in Oracle PL SQL?

Oracle CREATE VIEW syntax

  1. CREATE [OR REPLACE] VIEW view_name [(column_aliases)] AS defining-query [WITH READ ONLY] [WITH CHECK OPTION]
  2. CREATE VIEW employee_yos AS SELECT employee_id, first_name || ‘ ‘ || last_name full_name, FLOOR( months_between( CURRENT_DATE, hire_date )/ 12 ) yos FROM employees;

What is view and types in Oracle?

A view is a virtual table because you can use it like a table in your SQL queries. Every view has columns with data types so you can execute a query against views or manage their contents (with some restrictions) using the INSERT , UPDATE , DELETE , and MERGE statements. Unlike a table, a view does not store any data.

How do I insert a view in SQL?

To insert data through view in multiple tables, we need to use the INSTEAD OF TRIGGER in SQL Server. An INSTEAD OF TRIGGER in SQL Server allows executing other statements specified in the trigger instead of an INSERT, DELETE, or UPDATE statement to a table or view.

How do I create a view in SQL script?

How to create a view in SQL with a single table

  1. CREATE VIEW view_name AS.
  2. SELECT column1, column2.
  3. FROM table_name.
  4. WHERE condition;

How do you write a view?

To create a view, a user must have the appropriate system privilege according to the specific implementation. CREATE VIEW view_name AS SELECT column1, column2….. FROM table_name WHERE [condition]; You can include multiple tables in your SELECT statement in a similar way as you use them in a normal SQL SELECT query.

How do you add views?

You can insert rows into a view only if the view is modifiable and contains no derived columns. The reason for the second restriction is that an inserted row must provide values for all columns, but the database server cannot tell how to distribute an inserted value through an expression.

What is a syntax for creating a view?

The syntax for the CREATE VIEW statement in SQL is: CREATE VIEW view_name AS SELECT columns FROM tables [WHERE conditions]; view_name.

How do I write a SQL view query?

The syntax for creating a view is as follows:

  1. CREATE VIEW “VIEW_NAME” AS “SQL Statement”;
  2. CREATE VIEW V_Customer. AS SELECT First_Name, Last_Name, Country. FROM Customer;
  3. CREATE VIEW V_REGION_SALES. AS SELECT A1.Region_Name REGION, SUM(A2.Sales) SALES. FROM Geography A1, Store_Information A2.

How do you create a view in SQL?

In Object Explorer, expand the database where you want to create your new view. Right-click the Views folder, then click New View…. In the Add Table dialog box, select the element or elements that you want to include in your new view from one of the following tabs: Tables, Views, Functions, and Synonyms.

Which of the following conditions will create read only views?

Read-Only Views A view will be read-only if its SELECT statement has any of the following characteristics: Specifies a row quantifier other than ALL (i.e., DISTINCT, FIRST, SKIP) Contains fields defined by subqueries or other expressions. Contains fields defined by aggregating functions and/or a GROUP BY clause.