Expressions in SELECT

Expressions transform data on the fly, letting you compute totals, differences, and other derived values directly in your query. An expression is any combination of values, operators, and functions that the database evaluates to produce a result. For example, "price + tax" is an expression that adds two column values together. SQL can calculate new values as part of the results using expressions. Common Operations SQL supports standard arithmetic operators that let you perform calculations directly within your queries. Practice: Expressions Put your expression skills to work by calculating a total cost from quantity and unit price. Expressions let you compute answers directly in the database rather than pulling raw numbers into a spreadsheet and calculating there, which is both faster and