Syntax
AVG([DISTINCT | ALL] expr)
Purpose
AVG() returns the average value of a specified group. NULLs are ignored. The DISTINCT option can be used to return the average of distinct values of expr. If no matching row is found, AVG() returns NULL.
Examples
obclient> SELECT * FROM oceanbasetest;
+----+------+------+
| id | ip | ip2 |
+----+------+------+
| 1 | 4 | NULL |
| 3 | 3 | NULL |
| 4 | 3 | NULL |
+----+------+------+
3 rows in set
obclient> SELECT AVG(ip2), AVG(ip), AVG(DISTINCT(ip)) FROM oceanbasetest;
+----------+---------+-------------------+
| AVG(ip2) | AVG(ip) | AVG(DISTINCT(ip)) |
+----------+---------+-------------------+
| NULL | 3.3333 | 3.5000 |
+----------+---------+-------------------+
1 row in set
obclient> SELECT AVG(DISTINCT(ip)),AVG(ip),AVG(ip2) FROM oceanbasetest;
+-------------------+---------+----------+
| AVG(DISTINCT(ip)) | AVG(ip) | AVG(ip2) |
+-------------------+---------+----------+
| 3.5000 | 3.3333 | NULL |
+-------------------+---------+----------+
1 row in set
