In a multiple-column sort, what is the order in which the columns are specified?

In a multiple-column sort, the columns are processed from left to right in the order they appear after the ORDER BY clause.

Here is how the logic works:

1. Primary Sort: SQL sorts the data based on the first column specified.
2. Secondary Sort: Only if there are rows with the exact same value in the first column does SQL look at the second column to determine their relative order.
3. Subsequent Sorts: This pattern continues for any additional columns listed.

Example Analysis

Based on your command history:

ORDER BY genre ASC, price DESC;

• Step 1: SQL first groups all "Mystery" books together and all "Technical" books together (Alphabetical order).
• Step 2: Within the "Mystery" group, it looks at the price. Since you specified DESC, it puts the most expensive Mystery book first.
• Step 3: It does the same for the "Technical" group, sorting those specific rows by price descending.

Key Rule: Each column can have its own direction (ASC or DESC). If you don't specify one, it defaults to ASC (ascending).