psql　

条件検索

blogapp=# select * from users where score > 4.0;
 id |  name  | score |  team
----+--------+-------+--------
  1 | yamada |   6.5 | red
  2 | satou  |   4.3 | green
  3 | sasaki |   8.2 | green
  5 | satou  |   4.2 | blue
  6 | sasaki |   7.6 | green
  7 | yamada |   5.7 | yellow
(6 行)

blogapp=# select * from users where name = 'yamada';
 id |  name  | score |  team
----+--------+-------+--------
  1 | yamada |   6.5 | red
  4 | yamada |   3.6 | red
  7 | yamada |   5.7 | yellow
(3 行)

並び順

blogapp=# select * from users order by score;
 id |  name  | score |  team
----+--------+-------+--------
  4 | yamada |   3.6 | red
  5 | satou  |   4.2 | blue
  2 | satou  |   4.3 | green
  7 | yamada |   5.7 | yellow
  1 | yamada |   6.5 | red
  6 | sasaki |   7.6 | green
  3 | sasaki |   8.2 | green
(7 行)

blogapp=# select * from users order by score desc;
 id |  name  | score |  team
----+--------+-------+--------
  3 | sasaki |   8.2 | green
  6 | sasaki |   7.6 | green
  1 | yamada |   6.5 | red
  7 | yamada |   5.7 | yellow
  2 | satou  |   4.3 | green
  5 | satou  |   4.2 | blue
  4 | yamada |   3.6 | red

offset

blogapp=# select * from users limit3 offset 3;
 id |  name  | score |  team
----+--------+-------+--------
  4 | yamada |   3.6 | red
  5 | satou  |   4.2 | blue
  6 | sasaki |   7.6 | green
  7 | yamada |   5.7 | yellow
(4 行)

レコード集計

blogapp=# select count(*) from users;
 count
-------
     7
(1 行)