SQL SELECT COUNT, SUM, AVG Statement with Example

SQL SELECT COUNT, SUM, AVG

• SELECT COUNT returns a count of the number of data values.
• SELECT SUM returns the sum of the data values.
• SELECT AVG returns the average of the data values.

The SQL SELECT COUNT, SUM, and AVG syntax

The general COUNT syntax is:

1. SELECT COUNT(column-name) FROM table-name

The general SUM syntax is:

1. SELECT SUM(column-name) FROM table-name

The general AVG syntax is:

1. SELECT AVG(column-name) FROM table-name
   

SQL SELECT COUNT, SUM, and AVG Examples

 1) example of Count Statement

mysql> select count(name) from person;
+-------------+
| count(name) |
+-------------+
|          11 |
+-------------+
1 row in set (0.00 sec)

2) Example of Sum Statement

mysql> select sum(age) from person;
+----------+
| sum(age) |
+----------+
|      226 |
+----------+
1 row in set (0.00 sec)

5) Example of Sum Statement with Distinct Clause

mysql> select sum(distinct age) from person;
+-------------------+
| sum(distinct age) |
+-------------------+
|               179 |
+-------------------+
1 row in set (0.00 sec)

3) Example of AVG Statement

mysql> select avg(age) from person;
+----------+
| avg(age) |
+----------+
|  22.6000 |
+----------+
1 row in set (0.00 sec)

4) Example of AVG statement with distinct Clause

mysql> select avg(distinct age) from person;
+-------------------+
| avg(distinct age) |
+-------------------+
|           22.3750 |
+-------------------+
1 row in set (0.00 sec)