Sql Queries For Mere Mortals [REAL BLUEPRINT]

Use the DISTINCT keyword right after SELECT to clean up redundant rows in your results.

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 SQL Queries for Mere Mortals

Use these to total up sales or count your users. Use the DISTINCT keyword right after SELECT to

SQL Queries for Mere Mortals: A Hands-On Guide to Data ... - InformIT Summarizing and Grouping Use these to total up

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.

A filter for grouped data. While WHERE filters rows, HAVING filters the results of your calculations (e.g., "Only show regions with more than $10,000 in sales"). Pro Tips for "Mere Mortals"

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