• Introduction
  • 1. How to Retrieve Data From a Single Table
  • 2. How to Retrieve Data from Multiple Tables
  • 3. Using Functions
  • 4. How to Insert, Update, Delete Data in Tables
  • 5. Summary Queries and Aggregate Functions
  • 6. Working With Subqueries
  • 7. SQL Views
  • 8. SQL Indexes
  • Glossary
  • Index
  • Download
  • Translations
  • Grouping Data
    • 5.2

    Grouping Data

    Using the GROUP BY Clause

    • Group rows based on a column(s) or expression(s).
    • If you use an aggregate function with a GROUP BY clause, the aggregation is calculated for each group.

    Table 1. GROUP BY Function

    Aggregate Function Order of Execution Description

    GROUP BY

    3

    Groups rows of a result set based on columns or expressions separated by commas.

    Filtering With WHERE And HAVING

    • Notice the order of execution. GROUP BY happens before WHERE but after HAVING.
    • It is possible to use WHERE and HAVING in the same statement. They are not mutually exclusive.

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