Using Group Functions in the ORDER BY Clause in MySQL

Q

Can Group Functions Be Used in the ORDER BY Clause in MySQL?

✍: FYIcenter.com

A

If the query output is aggregated as groups, you can sort the groups by using group functions in the ORDER BY clause. The following statement returns how many links were created in each year in each tag. The group output is sorted by the count in each group in descending order:

mysql> SELECT tag, YEAR(created), COUNT(*) 
   FROM fyi_links GROUP BY tag, YEAR(created) 
   ORDER BY COUNT(*) DESC;
+------+---------------+----------+
| tag  | YEAR(created) | COUNT(*) |
+------+---------------+----------+
| DBA  |          2006 |        2 |
| DEV  |          2006 |        1 |
| SQA  |          2006 |        1 |
| DBA  |          2005 |        1 |
| DEV  |          2004 |        1 |
| SQA  |          2003 |        1 |
+------+---------------+----------+
6 rows in set (0.00 sec)

⇒ SELECT Statements with JOIN and Subqueries in MySQL

⇐ Using Multiple Columns in GROUP BY in MySQL

⇑ SELECT Query Statements with GROUP BY in MySQL

⇑⇑ MySQL Database Tutorials

2017-12-31, 2515🔥, 0💬

Dividing Query Output into Groups in MySQL
How To Divide Query Output into Groups in MySQL? You can divide query output into multiple groups with the GROUP BY clause. It allows you specify a column as the grouping criteria, so that rows with the same value in that column will be considered as a single group. When the GROUP BY clause is speci... 2017-10-16, 3027🔥, 0💬

Using Multiple Columns in GROUP BY in MySQL
Can Multiple Columns Be Used in GROUP BY in MySQL? If you want to break your output into smaller groups, if you specify multiple column names or expressions in the GROUP BY clause. Output in each group must satisfy a specific combination of the expressions listed in the GROUP BY clause. The more col... 2017-10-16, 2999🔥, 0💬

SELECT Statements with JOIN and Subqueries in MySQL
Where to find answers to frequently asked questions on SELECT Statements with JOIN and Subqueries in MySQL? Here is a list of frequently asked questions and their answers compiled by FYIcenter.com DBA team on SELECT Statements with JOIN and Subqueries in MySQL. Clear answers are provided with tutori... 2017-12-31, 2858🔥, 0💬

Using Table Alias Names in MySQL
How To Define and Use Table Alias Names in MySQL? When column names need to be prefixed with table names, you can define table alias name and use them to prefix column names as shown in the following select statement: mysql> SELECT l.id, l.url, r.comment FROM fyi_links l INNER JOIN fyi_rates ... 2017-12-31, 2850🔥, 0💬

Query with an Inner Join in MySQL
How To Write a Query with an Inner Join in MySQL? If you want to query from two tables with an inner join, you can use the INNER JOIN ... ON clause in the FROM clause. The tutorial exercise below creates another testing table and returns output with an inner join from two tables: fyi_links and fyi.r... 2017-12-31, 2715🔥, 0💬

Group Functions with Non-group Selections in MySQL
Can Group Functions Be Mixed with Non-group Selection Fields in MySQL? If a group function is used in the SELECT clause, all other selection fields must be group level fields. Non-group fields can not be mixed with group fields in the SELECT clause. The script below gives you an example of invalid S... 2017-10-16, 2715🔥, 0💬

Apply Filtering Criteria at Group Level in MySQL
How To Apply Filtering Criteria at Group Level in MySQL? If you want to return only specific groups from the query, you can apply filtering criteria at the group level by using the HAVING clause inside the GROUP BY clause. Note group functions can also be used in HAVING conditions. The following tut... 2017-10-16, 2706🔥, 0💬

Query with a Left Outer Join in MySQL
How To Write a Query with a Left Outer Join in MySQL? If you want to query from two tables with a left outer join, you can use the LEFT OUTER JOIN ... ON clause in the FROM clause. The following query returns output with a left outer join from two tables: fyi_links and fyi_rates. The join condition ... 2017-09-28, 2679🔥, 0💬

Types of Table Joins in MySQL
How To Join Two Tables in a Single Query in MySQL? Two tables can be joined together in a query in 4 ways: Inner Join: Returns only rows from both tables that satisfy the join condition. Left Outer Join: Returns rows from both tables that satisfy the join condition, and the rest of rows from the fir... 2017-12-31, 2674🔥, 0💬

All rights in the contents of this web site are reserved by the individual author. fyicenter.com does not guarantee the truthfulness, accuracy, or reliability of any contents.