Sql Queries For Mere Mortals Apr 2026

Don't try to fit a "ten-pound sack in a five-pound box." Ensure you aren't trying to store long text in a short character field.

While SELECT * is fast, explicitly naming your columns is safer and often faster for the database.

SQL Queries for Mere Mortals: A Hands-On Guide to Data ... - InformIT SQL Queries for Mere Mortals

Finding what is in one group but not the other (e.g., customers who have never placed an order). 2. Drafting the Statement

Use these to total up sales or count your users. Don't try to fit a "ten-pound sack in a five-pound box

Includes all records from one table, even if there is no match in the other (useful for finding "missing" data, like products that haven't sold). 4. Summarizing and Grouping

Use the DISTINCT keyword right after SELECT to clean up redundant rows in your results. - InformIT Finding what is in one group

Essential when using aggregates. It tells the database how to bucket the results (e.g., "Show me the total sales per region").