CREATE VIEW syntax in SQL - Step-by-Step Execution

Concept Flow - CREATE VIEW syntax

Write SELECT query

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Use CREATE VIEW name AS

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Database stores view definition

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Querying view runs stored SELECT

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Return result set as if table

You write a SELECT query, then create a view with that query. The database stores it. When you query the view, it runs the stored SELECT and returns results like a table.

Execution Sample

SQL

CREATE VIEW active_users AS
SELECT id, name FROM users WHERE active = 1;

This creates a view named active_users that shows only users who are active.

Execution Table

Step	Action	Query/Command	Result/State
1	Write SELECT query	SELECT id, name FROM users WHERE active = 1	Query ready to define view
2	Create view with query	CREATE VIEW active_users AS SELECT id, name FROM users WHERE active = 1	View 'active_users' stored in database
3	Query the view	SELECT * FROM active_users	Runs stored SELECT, returns active users
4	View result	id | name	Rows of active users from users table
5	Exit	N/A	View acts like a virtual table

💡 View creation ends after storing the SELECT query; querying the view runs that query.

Variable Tracker

Variable	Start	After Step 2	After Step 3	Final
View Definition	None	SELECT id, name FROM users WHERE active = 1	Same stored query	Same stored query
Query Result	None	None	Rows where active=1	Rows where active=1

Key Moments - 2 Insights

Why does the CREATE VIEW command not return rows immediately?

Because CREATE VIEW only stores the SELECT query as a definition (see execution_table step 2). It does not run the query until you select from the view (step 3).

Can you update data directly in a view?

Usually no, because a view is a virtual table showing results of a SELECT (execution_table step 4). You update the underlying tables instead.

Visual Quiz - 3 Questions

Look at the execution table, what happens at step 2?

A The view runs the SELECT query and returns rows

B The view definition is stored in the database

C The view is deleted

D The underlying table is modified

💡 Hint

Check execution_table row with Step 2 describing storing the view definition

At which step does querying the view actually run the stored SELECT query?

A Step 1

B Step 2

C Step 3

D Step 5

💡 Hint

Look at execution_table step 3 where the view is queried

If the SELECT query inside the view changes, what must you do to update the view?

A Run CREATE VIEW again with new query

B Just query the view again

C Update the underlying table only

D Drop the view and do nothing

💡 Hint

View stores the SELECT query at creation (see variable_tracker 'View Definition')

Concept Snapshot

CREATE VIEW view_name AS SELECT ...;
- Defines a virtual table storing a SELECT query
- Does not run query until view is queried
- Querying view runs stored SELECT and returns results
- Views simplify complex queries and reuse
- Views do not store data themselves

Full Transcript

The CREATE VIEW syntax lets you save a SELECT query as a virtual table called a view. First, you write the SELECT query you want. Then you use CREATE VIEW view_name AS followed by that query. The database stores this query as the view's definition. When you later query the view, the database runs the stored SELECT query and returns the results as if it were a table. The view itself does not store data, it just shows data from the underlying tables. This helps reuse queries and simplify complex data access. You cannot update data directly in a view; you update the original tables instead. To change the view's query, you recreate the view with a new SELECT statement.