How can we create a MySQL view using subquery?

To illustrate how to create a MySQL view using a subquery, we use the following data from the "Cars" table -

mysql> select * from cars;
+------+--------------+---------+
| ID   | Name         | Price   |
+------+--------------+---------+
|    1 | Nexa         | 750000  |
|    2 | Maruti Swift | 450000  |
|    3 | BMW          | 4450000 |
|    4 | VOLVO        | 2250000 |
|    5 | Alto         | 250000  |
|    6 | Skoda        | 1250000 |
|    7 | Toyota       | 2400000 |
|    8 | Ford         | 1100000 |
+------+--------------+---------+
8 rows in set (0.08 sec)

Now, the following query will use the subquery The query creates a view called "cars_avgprice" and the subquery will provide values ​​to the view. Subqueries must be enclosed in parentheses.

mysql> Create view cars_avgprice AS SELECT NAME, Price FROM Cars WHERE price > (SELECT AVG(Price) from cars);
Query OK, 0 rows affected (0.12 sec)

mysql> Select * from cars_avgprice;
+--------+---------+
| NAME   | Price   |
+--------+---------+
| BMW    | 4450000 |
| VOLVO  | 2250000 |
| Toyota | 2400000 |
+--------+---------+
3 rows in set (0.03 sec)

If we run the above subquery alone, we can understand how the view gets its value -

mysql> Select AVG(Price) from cars;
+--------------+
| AVG(Price)   |
+--------------+
| 1612500.0000 |
+--------------+
1 row in set (0.00 sec)

That's why the view "cars_avgprice" contains prices that are higher than the average price (i.e. 1612500) Car List.

The above is the detailed content of How can we create a MySQL view using subquery?. For more information, please follow other related articles on the PHP Chinese website!