Queries with Expressions

Now that we understand the basics of querying, we can really start to dive deeper by building more complex statements as expressions. These expressions can be mathematical or even basic string functions.

When writing expressions, we should use the AS keyword to create an alias for our expression, which makes our statements easier to read. This can be used on columns or tables.

The following statement is a great example of an expression:

SELECT particle_speed / 2.0 AS half_particle_speed
FROM physics_data
WHERE ABS(particle_position) * 10.0 > 500;

Obviously this is a pretty complex expression, but that’s not so much the point; more so, it shows the capabilities of what’s possible.

Next: Lesson 10 & 11