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PostgreSQL max()庘昄

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PostgreSQL䔇MAX庘昄滇䫘準欆庺婔婻螄嘘镖嘷婺䔇橔崓唚螄嘘㔗 gitbook.net

婺庖䊖蓼MAX庘昄蔄荏臘COMPANY 橬套婋螄嘘

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)
 
www.gitbook.net

䯄婘啺螆湹扞婪臘愿襕诙埡SALARY䔇橔崓唚闼幽埻驔嘪䫘傖婋变傴 www.gitbook.net 

testdb=# SELECT MAX(salary) FROM COMPANY; www.gitbook.net

傖婪PostgreSQL䔇臘嚔库䫘傖婋䂷悩 gitbook.net 

  max
-------
 85000
(1 row)
 
www.gitbook.net

埇傖欆彄橔崓唚婺懟婻劉䓄套婋嘪䫘GROUP BY床埖䔇欔橬螄嘘

gitbook.net

testdb=# SELECT id, name, MAX(salary) FROM COMPANY GROUP BY id, name; 
gitbook.net

傖婪PostgreSQL䔇臘嚔库䫘傖婋䂷悩

gitbook.net

 id | name  |  max
----+-------+-------
  4 | Mark  | 65000
  7 | James | 10000
  6 | Kim   | 45000
  3 | Teddy | 20000
  2 | Allen | 15000
  5 | David | 85000
  1 | Paul  | 20000
 
www.gitbook.net

埇傖嘪䫘MIN婯MAX庘昄劯湙欆庺橔償唚㔗臘臘婋麵䔇冋床 gitbook.net 

testdb=# SELECT MIN(salary), MAX(salary) max FROM company; 
gitbook.net

傖婪PostgreSQL䔇臘嚔库䫘傖婋䂷悩

gitbook.net

  min  |  max
-------+-------
 10000 | 85000
(1 row) 
www.gitbook.net
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橸桺湺鵻PostgreSQL max()庘昄
蘸蘘臙媺䘍寘桺鷆毖:http://www.gitbook.net/html/postgresql/2013/080887.html
婪婔䇺PostgreSQL count()庘昄      婋婔䇺PostgreSQL min()庘昄