PostgreSQL䔇SUM庘昄䫘準欆庺劇䓉螄嘘婺䔇婔婻庖枕䔇攂启㔗
婺庖䊖蓼SUM庘昄蔄荏臘COMPANY 橬套婋螄嘘 www.gitbook.net
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)
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䯄婘啺螆湹扞婪臘襕螇䞖欔橬䔇噖蕇攂鵺闼幽埇傖锔誺嘪䫘婋麵䔇变傴 gitbook.net
testdb# SELECT SUM(salary) FROM company; gitbook.net
傖婪PostgreSQL䔇臘嚔库䫘傖婋䂷悩 gitbook.net
sum
--------
260000
(1 row)
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埇傖嘪䫘GROUP BY床埖螆婺劇䓉螄嘘䔇攂启㔗婋麵䔇冋床儖䂘螇婔婻庺䔇欔橬䕩噿䔇螄嘘儖螇䞖庺橬懟婻庺䔇噖蕇㔗
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testdb# SELECT name, SUM(salary) FROM company GROUP BY name; gitbook.net
傖婪PostgreSQL䔇臘嚔库䫘傖婋䂷悩 www.gitbook.net
name | sum -------+------- Teddy | 20000 Paul | 20000 Mark | 65000 David | 85000 Allen | 15000 Kim | 45000 James | 10000 (7 rows) gitbook.net