How to select multiple rows filled with constants?

Question

Selecting constants without referring to a table is perfectly legal in an SQL statement:

SELECT 1, 2, 3

The result set that the latter retu

Answer 1

In MySQL, you can do: values (1,2), (3, 4);

mysql> values (1,2), (3, 4);
+---+---+
| 1 | 2 |
+---+---+
| 1 | 2 |
| 3 | 4 |
+---+---+
2 rows in set (0.004 sec)

With MySQL 8, it is also possible to give the column names:

mysql> SELECT * FROM (SELECT 1, 2, 3, 4) AS dt (a, b, c, d);
+---+---+---+---+
| a | b | c | d |
+---+---+---+---+
| 1 | 2 | 3 | 4 |
+---+---+---+---+

Answer 2

Here a way to create custom rows directly with MySQL request SELECT :

SELECT ALL *
FROM (
    VALUES
        ROW (1, 2, 3),
        ROW (4, 5, 6),
        ROW (7, 8, 9)
) AS dummy (c1, c2, c3)

Gives us a table dummy :

c1   c2   c3
-------------
 1    2    3
 4    5    6
 7    8    9

Tested with MySQL 8

Answer 3

For Microsoft SQL Server or PostgreSQL you may want to try this syntax

SELECT constants FROM (VALUES ('foo@gmail.com'), ('bar@gmail.com'), ('baz@gmail.com')) AS MyTable(constants)

You can also view an SQL Fiddle here: http://www.sqlfiddle.com/#!17/9eecb/34703/0

Answer 4

In PostgreSQL, you can do:

SELECT  *
FROM    (
        VALUES
        (1, 2),
        (3, 4)
        ) AS q (col1, col2)

In other systems, just use UNION ALL:

SELECT  1 AS col1, 2 AS col2
-- FROM    dual
-- uncomment the line above if in Oracle
UNION ALL
SELECT  3 AS col1, 3 AS col2
-- FROM    dual
-- uncomment the line above if in Oracle

In Oracle, SQL Server and PostgreSQL, you also can generate recordsets of arbitrary number of rows (providable with an external variable):

SELECT  level
FROM    dual
CONNECT BY
        level <= :n

in Oracle,

WITH    q (l) AS
        (
        SELECT  1
        UNION ALL
        SELECT  l + 1
        FROM    q
        WHERE   l < @n
        )
SELECT  l
FROM    q
-- OPTION (MAXRECURSION 0)
-- uncomment line above if @n >= 100

in SQL Server,

SELECT  l
FROM    generate_series(1, $n) l

in PostgreSQL.

Answer 5

Here is how to do it using the XML features of DB2

SELECT *
FROM
XMLTABLE ('$doc/ROWSET/ROW' PASSING XMLPARSE ( DOCUMENT '
<ROWSET>
  <ROW>
    <A val="1" /> <B val="2" /> <C val="3" />
  </ROW>
  <ROW>
    <A val="4" /> <B val="5" /> <C val="6" />
  </ROW>
  <ROW>
    <A val="7" /> <B val="8" /> <C val="9" />
  </ROW>
</ROWSET>
') AS "doc"
   COLUMNS 
      "A" INT PATH 'A/@val',
      "B" INT PATH 'B/@val',
      "C" INT PATH 'C/@val'
) 
AS X
;

Answer 6

Following bare VALUES command works for me in PostgreSQL:

VALUES (1,2,3), (4,5,6), (7,8,9)