Lesson 2: Filtering data

Use of WHERE Statement

To filter certain results from being returned, we need to use a WHERE clause in the query. The clause is applied to each row of data by checking specific column values to determine whether it should be included in the results or no. Using the table Customers data;

customer_id	first_name	last_name	age	country
1	John	Doe	31	USA
2	Robert	Luna	22	USA
3	David	Robinson	22	UK
4	John	Reinhardt	25	UK
5	Betty	Doe	28	UAE

If we wish to get specific details such as a given age range, the WHERE clause can be used for this; SELECT * FROM Customers WHERE age > 23

customer_id	first_name	last_name	age	country
1	John	Doe	31	USA
2	Robert	Luna	22	USA
3	David	Robinson	22	UK
4	John	Reinhardt	25	UK
5	Betty	Doe	28	UAE