COUNT()

Returns the number of values in the given expression.

See also: Functions in 10.6 CS, in 10.5 ES, in 10.5 CS, in 10.4 ES, in 10.4 CS, in 10.3 ES, in 10.3 CS, in 10.2 ES, and in 10.2 CS

DETAILS

CHANGE HISTORY

Release Series

History

10.6 Community

  • Present starting in MariaDB Community Server 10.6.0.

10.5 Enterprise

  • Present starting in MariaDB Enterprise Server 10.5.3-1.

10.5 Community

  • Present starting in MariaDB Community Server 10.5.0.

10.4 Enterprise

  • Present starting in MariaDB Enterprise Server 10.4.6-1.

10.4 Community

  • Present starting in MariaDB Community Server 10.4.0.

10.3 Enterprise

  • Present starting in MariaDB Enterprise Server 10.3.16-1.

10.3 Community

  • Present starting in MariaDB Community Server 10.3.0.

10.2 Enterprise

  • Present starting in MariaDB Enterprise Server 10.2.25-1.

10.2 Community

  • Present starting in MariaDB Community Server 10.2.0.

EXAMPLES

CREATE TABLE t (a INT);
INSERT INTO t VALUES (1), (2), (3);
SELECT COUNT(a) FROM t;
+----------+
| COUNT(a) |
+----------+
|        3 |
+----------+

As Window Function

CREATE TABLE t1 (a INT, b INT);
INSERT INTO t1(a,b) VALUES
  (1,3), (1,5), (8,2), (5,7), (5,6),
  (10,1), (6,4), (3,9), (3,9), (7,2),
  (7,5), (2,6), (9,10), (9,5), (4,8);
SELECT a, COUNT(a) OVER (PARTITION BY b) AS count_a,
       AVG(b) OVER (PARTITION BY a) as avg_b
FROM t1
GROUP BY a;
+------+---------+---------+
| a    | count_a | avg_b   |
+------+---------+---------+
|    1 |       1 |  3.0000 |
|    2 |       1 |  6.0000 |
|    3 |       1 |  9.0000 |
|    4 |       1 |  8.0000 |
|    5 |       1 |  7.0000 |
|    6 |       1 |  4.0000 |
|    7 |       2 |  2.0000 |
|    8 |       2 |  2.0000 |
|    9 |       1 | 10.0000 |
|   10 |       1 |  1.0000 |
+------+---------+---------+

EXTERNAL REFERENCES