Querying from views in MySQL - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a view in a database?

A view is like a saved query that looks like a table. It shows data from one or more tables but does not store data itself.

beginner

How do you select data from a view named employee_view?

You use a SELECT statement just like with a table: <br>SELECT * FROM employee_view;

intermediate

Can you update data directly through a view?

Sometimes yes, if the view is simple and based on one table. But complex views or those with joins usually cannot be updated directly.

beginner

Why use views instead of querying tables directly?

Views simplify complex queries, hide sensitive columns, and provide a consistent way to look at data.

beginner

Write a simple SQL to create a view named active_customers showing customers with status 'active'.

CREATE VIEW active_customers AS SELECT * FROM customers WHERE status = 'active';

What does a view in SQL represent?

A A stored table with data

B A backup of the database

C A saved query that looks like a table

D A user account

A view is a saved query that behaves like a table but does not store data itself.

Which SQL command is used to get data from a view named sales_view?

A SELECT * FROM sales_view;

B GET * FROM sales_view;

C SHOW sales_view;

D READ sales_view;

You use SELECT to query data from a view just like a table.

Can you always update data through a view?

A Yes, always

B No, never

C Only if the view has more than one table

D Only if the view is simple and based on one table

Updates through views are allowed only if the view is simple and based on a single table.

Why might you use a view instead of querying tables directly?

A To hide sensitive data and simplify queries

B To make queries more complex

C To store data permanently

D To delete data faster

Views help simplify queries and can hide sensitive columns from users.

Which of these is the correct syntax to create a view?

A CREATE TABLE view_name AS SELECT ...;

B CREATE VIEW view_name AS SELECT ...;

C MAKE VIEW view_name SELECT ...;

D NEW VIEW view_name AS SELECT ...;

The correct syntax to create a view is CREATE VIEW view_name AS SELECT ...

Explain what a database view is and why it is useful.

Think about how a view acts like a window to data.

Describe how to query data from a view and mention any limitations on updating data through views.

Consider how views behave like tables but with some restrictions.