SELECT statement

table_name [ [ AS ] alias [ ( column_alias [, ...] ) ] ]

[ INNER ] JOIN
LEFT [ OUTER ] JOIN
RIGHT [ OUTER ] JOIN
FULL [ OUTER ] JOIN
CROSS JOIN

SELECT a, b
FROM (
  SELECT a, MAX(b) AS b FROM t GROUP BY a
) AS x;

WITH x AS (SELECT a, MAX(b) AS b FROM t GROUP BY a)
SELECT a, b FROM x;

WITH
  t1 AS (SELECT a, MAX(b) AS b FROM x GROUP BY a),
  t2 AS (SELECT a, AVG(d) AS d FROM y GROUP BY a)
SELECT t1.*, t2.*
FROM t1
JOIN t2 ON t1.a = t2.a;

WITH
  x AS (SELECT a FROM t),
  y AS (SELECT a AS b FROM x),
  z AS (SELECT b AS c FROM y)
SELECT c FROM z;

SELECT count(*), nationkey FROM customer GROUP BY 2;

SELECT count(*), nationkey FROM customer GROUP BY nationkey;

SELECT count(*) FROM customer GROUP BY mktsegment;

 _col0
-------
 29968
 30142
 30189
 29949
 29752
(5 rows)

SELECT * FROM shipping;

 origin_state | origin_zip | destination_state | destination_zip | package_weight
--------------+------------+-------------------+-----------------+----------------
 California   |      94131 | New Jersey        |            8648 |             13
 California   |      94131 | New Jersey        |            8540 |             42
 New Jersey   |       7081 | Connecticut       |            6708 |            225
 California   |      90210 | Connecticut       |            6927 |           1337
 California   |      94131 | Colorado          |           80302 |              5
 New York     |      10002 | New Jersey        |            8540 |              3
(6 rows)

SELECT origin_state, origin_zip, destination_state, sum(package_weight)
FROM shipping
GROUP BY GROUPING SETS (
    (origin_state),
    (origin_state, origin_zip),
    (destination_state));

 origin_state | origin_zip | destination_state | _col0
--------------+------------+-------------------+-------
 New Jersey   | NULL       | NULL              |   225
 California   | NULL       | NULL              |  1397
 New York     | NULL       | NULL              |     3
 California   |      90210 | NULL              |  1337
 California   |      94131 | NULL              |    60
 New Jersey   |       7081 | NULL              |   225
 New York     |      10002 | NULL              |     3
 NULL         | NULL       | Colorado          |     5
 NULL         | NULL       | New Jersey        |    58
 NULL         | NULL       | Connecticut       |  1562
(10 rows)

SELECT origin_state, NULL, NULL, sum(package_weight)
FROM shipping GROUP BY origin_state

UNION ALL

SELECT origin_state, origin_zip, NULL, sum(package_weight)
FROM shipping GROUP BY origin_state, origin_zip

UNION ALL

SELECT NULL, NULL, destination_state, sum(package_weight)
FROM shipping GROUP BY destination_state;

SELECT origin_state, destination_state, sum(package_weight)
FROM shipping
GROUP BY CUBE (origin_state, destination_state);

SELECT origin_state, destination_state, sum(package_weight)
FROM shipping
GROUP BY GROUPING SETS (
    (origin_state, destination_state),
    (origin_state),
    (destination_state),
    ());

 origin_state | destination_state | _col0
--------------+-------------------+-------
 California   | New Jersey        |    55
 California   | Colorado          |     5
 New York     | New Jersey        |     3
 New Jersey   | Connecticut       |   225
 California   | Connecticut       |  1337
 California   | NULL              |  1397
 New York     | NULL              |     3
 New Jersey   | NULL              |   225
 NULL         | New Jersey        |    58
 NULL         | Connecticut       |  1562
 NULL         | Colorado          |     5
 NULL         | NULL              |  1625
(12 rows)

SELECT origin_state, origin_zip, sum(package_weight)
FROM shipping
GROUP BY ROLLUP (origin_state, origin_zip);

 origin_state | origin_zip | _col2
--------------+------------+-------
 California   |      94131 |    60
 California   |      90210 |  1337
 New Jersey   |       7081 |   225
 New York     |      10002 |     3
 California   | NULL       |  1397
 New York     | NULL       |     3
 New Jersey   | NULL       |   225
 NULL         | NULL       |  1625
(8 rows)

SELECT origin_state, origin_zip, sum(package_weight)
FROM shipping
GROUP BY GROUPING SETS ((origin_state, origin_zip), (origin_state), ());

SELECT origin_state, destination_state, origin_zip, sum(package_weight)
FROM shipping
GROUP BY
    GROUPING SETS ((origin_state, destination_state)),
    ROLLUP (origin_zip);

SELECT origin_state, destination_state, origin_zip, sum(package_weight)
FROM shipping
GROUP BY
    GROUPING SETS ((origin_state, destination_state)),
    GROUPING SETS ((origin_zip), ());

SELECT origin_state, destination_state, origin_zip, sum(package_weight)
FROM shipping
GROUP BY GROUPING SETS (
    (origin_state, destination_state, origin_zip),
    (origin_state, destination_state));

 origin_state | destination_state | origin_zip | _col3
--------------+-------------------+------------+-------
 New York     | New Jersey        |      10002 |     3
 California   | New Jersey        |      94131 |    55
 New Jersey   | Connecticut       |       7081 |   225
 California   | Connecticut       |      90210 |  1337
 California   | Colorado          |      94131 |     5
 New York     | New Jersey        | NULL       |     3
 New Jersey   | Connecticut       | NULL       |   225
 California   | Colorado          | NULL       |     5
 California   | Connecticut       | NULL       |  1337
 California   | New Jersey        | NULL       |    55
(10 rows)

SELECT origin_state, destination_state, origin_zip, sum(package_weight)
FROM shipping
GROUP BY ALL
    CUBE (origin_state, destination_state),
    ROLLUP (origin_state, origin_zip);

SELECT origin_state, destination_state, origin_zip, sum(package_weight)
FROM shipping
GROUP BY GROUPING SETS (
    (origin_state, destination_state, origin_zip),
    (origin_state, origin_zip),
    (origin_state, destination_state, origin_zip),
    (origin_state, origin_zip),
    (origin_state, destination_state),
    (origin_state),
    (origin_state, destination_state),
    (origin_state),
    (origin_state, destination_state),
    (origin_state),
    (destination_state),
    ());

SELECT origin_state, destination_state, origin_zip, sum(package_weight)
FROM shipping
GROUP BY DISTINCT
    CUBE (origin_state, destination_state),
    ROLLUP (origin_state, origin_zip);

SELECT origin_state, destination_state, origin_zip, sum(package_weight)
FROM shipping
GROUP BY GROUPING SETS (
    (origin_state, destination_state, origin_zip),
    (origin_state, origin_zip),
    (origin_state, destination_state),
    (origin_state),
    (destination_state),
    ());

SELECT origin_state, origin_zip, destination_state, sum(package_weight),
       grouping(origin_state, origin_zip, destination_state)
FROM shipping
GROUP BY GROUPING SETS (
        (origin_state),
        (origin_state, origin_zip),
        (destination_state));

origin_state | origin_zip | destination_state | _col3 | _col4
--------------+------------+-------------------+-------+-------
California   | NULL       | NULL              |  1397 |     3
New Jersey   | NULL       | NULL              |   225 |     3
New York     | NULL       | NULL              |     3 |     3
California   |      94131 | NULL              |    60 |     1
New Jersey   |       7081 | NULL              |   225 |     1
California   |      90210 | NULL              |  1337 |     1
New York     |      10002 | NULL              |     3 |     1
NULL         | NULL       | New Jersey        |    58 |     6
NULL         | NULL       | Connecticut       |  1562 |     6
NULL         | NULL       | Colorado          |     5 |     6
(10 rows)

query UNION [ALL | DISTINCT] query

query INTERSECT [DISTINCT] query

query EXCEPT [DISTINCT] query

SELECT 13
UNION
SELECT 42;

 _col0
-------
    13
    42
(2 rows)

SELECT 13
UNION
SELECT * FROM (VALUES 42, 13);

 _col0
-------
    13
    42
(2 rows)

SELECT 13
UNION ALL
SELECT * FROM (VALUES 42, 13);

 _col0
-------
    13
    42
    13
(2 rows)

SELECT * FROM (VALUES 13, 42)
INTERSECT
SELECT 13;

 _col0
-------
    13
(2 rows)

SELECT * FROM (VALUES 13, 42)
EXCEPT
SELECT 13;

 _col0
-------
   42
(2 rows)

ORDER BY expression [ ASC | DESC ] [ NULLS { FIRST | LAST } ] [, ...]

OFFSET count [ ROW | ROWS ]

SELECT name FROM nation ORDER BY name OFFSET 22;

      name
----------------
 UNITED KINGDOM
 UNITED STATES
 VIETNAM
(3 rows)

LIMIT { count | ALL }

SELECT orderdate FROM orders LIMIT 5;

 o_orderdate
-------------
 1996-04-14
 1992-01-15
 1995-02-01
 1995-11-12
 1992-04-26
(5 rows)

SELECT *
FROM users TABLESAMPLE BERNOULLI (50);

SELECT *
FROM users TABLESAMPLE SYSTEM (75);

SELECT o.*, i.*
FROM orders o TABLESAMPLE SYSTEM (10)
JOIN lineitem i TABLESAMPLE BERNOULLI (40)
  ON o.orderkey = i.orderkey;

SELECT student, score
FROM tests
CROSS JOIN UNNEST(scores) AS t (score);

SELECT numbers, animals, n, a
FROM (
  VALUES
    (ARRAY[2, 5], ARRAY['dog', 'cat', 'bird']),
    (ARRAY[7, 8, 9], ARRAY['cow', 'pig'])
) AS x (numbers, animals)
CROSS JOIN UNNEST(numbers, animals) AS t (n, a);

SELECT numbers, n, a
FROM (
  VALUES
    (ARRAY[2, 5]),
    (ARRAY[7, 8, 9])
) AS x (numbers)
CROSS JOIN UNNEST(numbers) WITH ORDINALITY AS t (n, a);

  numbers  | n | a
-----------+---+---
 [2, 5]    | 2 | 1
 [2, 5]    | 5 | 2
 [7, 8, 9] | 7 | 1
 [7, 8, 9] | 8 | 2
 [7, 8, 9] | 9 | 3
(5 rows)

SELECT
    animals, a, n
FROM (
    VALUES
        (MAP(ARRAY['dog', 'cat', 'bird'], ARRAY[1, 2, 0])),
        (MAP(ARRAY['dog', 'cat'], ARRAY[4, 5]))
) AS x (animals)
CROSS JOIN UNNEST(animals) AS t (a, n);

           animals          |  a   | n
----------------------------+------+---
 {"cat":2,"bird":0,"dog":1} | dog  | 1
 {"cat":2,"bird":0,"dog":1} | cat  | 2
 {"cat":2,"bird":0,"dog":1} | bird | 0
 {"cat":5,"dog":4}          | dog  | 4
 {"cat":5,"dog":4}          | cat  | 5
(5 rows)

SELECT n.name AS nation, r.name AS region
FROM nation AS n
CROSS JOIN region AS r
ORDER BY 1, 2;

     nation     |   region
----------------+-------------
 ALGERIA        | AFRICA
 ALGERIA        | AMERICA
 ALGERIA        | ASIA
 ALGERIA        | EUROPE
 ALGERIA        | MIDDLE EAST
 ARGENTINA      | AFRICA
 ARGENTINA      | AMERICA
...
(125 rows)

SELECT nation.name, region.name
FROM nation
CROSS JOIN region;

SELECT n.name, r.name
FROM nation AS n
CROSS JOIN region AS r;

SELECT n.name, r.name
FROM nation n
CROSS JOIN region r;

SELECT name
FROM nation
CROSS JOIN region;

SELECT *
FROM table_1
JOIN table_2
ON table_1.key_A = table_2.key_A AND table_1.key_B = table_2.key_B

SELECT *
FROM table_1
JOIN table_2
USING (key_A, key_B)

SELECT *
FROM (
    VALUES
        (1, 3, 10),
        (2, 4, 20)
) AS table_1 (key_A, key_B, y1)
LEFT JOIN (
    VALUES
        (1, 3, 100),
        (2, 4, 200)
) AS table_2 (key_A, key_B, y2)
USING (key_A, key_B)

-----------------------------

SELECT key_A, key_B, table_1.*, table_2.*
FROM (
    VALUES
        (1, 3, 10),
        (2, 4, 20)
) AS table_1 (key_A, key_B, y1)
LEFT JOIN (
    VALUES
        (1, 3, 100),
        (2, 4, 200)
) AS table_2 (key_A, key_B, y2)
USING (key_A, key_B)

 key_A | key_B | y1 | y2
-------+-------+----+-----
     1 |     3 | 10 | 100
     2 |     4 | 20 | 200
(2 rows)

SELECT name
FROM nation
WHERE EXISTS (SELECT * FROM region WHERE region.regionkey = nation.regionkey)

SELECT name
FROM nation
WHERE regionkey IN (SELECT regionkey FROM region)

SELECT name
FROM nation
WHERE regionkey = (SELECT max(regionkey) FROM region)