PostgreSQL – SUM Function
PostgreSQL SUM function is used to find out the sum of a field in various records.
To understand the SUM function consider the table COMPANY having records as follows −
testdb# select * from COMPANY; id | name | age | address | salary ----+-------+-----+-----------+-------- 1 | Paul | 32 | California| 20000 2 | Allen | 25 | Texas | 15000 3 | Teddy | 23 | Norway | 20000 4 | Mark | 25 | Rich-Mond | 65000 5 | David | 27 | Texas | 85000 6 | Kim | 22 | South-Hall| 45000 7 | James | 24 | Houston | 10000 (7 rows)
Now, based on the above table, suppose you want to calculate the total of all the salary, then you can do so by using the following command −
testdb# SELECT SUM(salary) FROM company;
The above given PostgreSQL statement will produce the following result −
sum -------- 260000 (1 row)
You can take the sum of various records set using the GROUP BY clause. The following example will sum up all the records related to a single person and you will have salary for each person.
testdb# SELECT name, SUM(salary) FROM company GROUP BY name;
The above given PostgreSQL statement will produce the following result −
name | sum -------+------- Teddy | 20000 Paul | 20000 Mark | 65000 David | 85000 Allen | 15000 Kim | 45000 James | 10000 (7 rows)
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