COUNT
Return the number of non-
NULL
values for an expression. The
ALL
keyword is optional. Use COUNT(*)
to return a count
of all of the rows in a table (regardless of NULL
values). COUNT( [ ALL ] expression)
COUNT(*)
The COUNT function works with all supported data types.
For example, count the rows in the
match
table:premdb=# SELECT COUNT(*) FROM match;
count
-------
8606
(1 row)
The following query groups by the winners
column in the
season
table to count the number of times a given team won the
league:
premdb=# SELECT winners, COUNT(winners)
FROM season WHERE winners IS NOT NULL GROUP BY winners ORDER BY 2 DESC;
winners | count
-------------------+-------
Manchester United | 13
Chelsea | 4
Arsenal | 3
Manchester City | 2
Blackburn Rovers | 1
Leicester City | 1
(6 rows)
Note: The COUNT function always returns a BIGINT data type.