HAVING床埖埇傖螷潏傸每锬庺臖庘昄䔇䂷悩严劽昊底溇傽䔇䬹垔臯㔗 www.gitbook.net

WHERE床埖欔锬彖䔇溇傽蔯HAVING床埖婄桹溇傽䫌GROUP BY床埖录傺䔇䂇㔗 gitbook.net

臺濘:

傖婋滇HAVING床埖婘SELECT昖臵䔇嘉䘞 gitbook.net

SELECT
FROM
WHERE
GROUP BY
HAVING
ORDER BY 
gitbook.net
 

HAVING床埖媙釂镕冻婘GROUP BY床埖庯婔婻昖臵幘媙釂噽套悩嘪䫘ORDER BY床埖㔗傖婋滇SELECT臺埖䔇臺濘寙拸HAVING床埖 gitbook.net

SELECT column1, column2
FROM table1, table2
WHERE [ conditions ]
GROUP BY column1, column2
HAVING [ conditions ]
ORDER BY column1, column2 gitbook.net 

冋床:

蔄荏臘COMPANY 橬套婋螄嘘

# 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)
 gitbook.net 

婋麵䔇冋床滆䴺螄嘘䔇劉䓄螇昄償庯2 gitbook.net

testdb-# SELECT NAME FROM COMPANY GROUP BY name HAVING count(name) < 2; www.gitbook.net 

認儖库䫘傖婋䂷悩

  name
 -------
  Teddy
  Paul
  Mark
  David
  Allen
  Kim
  James
(7 rows)
 
gitbook.net
 

䯄婘螷潏傸準录傺COMPANY 臘庯䔇婬溇螄嘘嘪䫘婋麵䔇INSERT臺埖 www.gitbook.net

INSERT INTO COMPANY VALUES (8, 'Paul', 24, 'Houston', 20000.00);
INSERT INTO COMPANY VALUES (9, 'James', 44, 'Norway', 5000.00);
INSERT INTO COMPANY VALUES (10, 'James', 45, 'Texas', 5000.00); 
gitbook.net
 

䯄婘潏傸䔇臘劉䓄麉崉䔇螄嘘

  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
   8 | Paul  |  24 | Houston      |  20000
   9 | James |  44 | Norway       |   5000
  10 | James |  45 | Texas        |   5000
(10 rows)
 
gitbook.net
 

婋麵䔇冋床嚔滆䴺劉䓄昄麟崓庯1䔇螄嘘 www.gitbook.net

testdb-# SELECT NAME FROM COMPANY GROUP BY name HAVING count(name) > 1; www.gitbook.net 

認儖库䫘傖婋䂷悩

 name
-------
 Paul
 James
(2 rows) www.gitbook.net