如何在Amazon Redshift中选择多行填充常量的行? [英] How to select multiple rows filled with constants in Amazon Redshift?

问题描述

我已经尝试了常见的PostgreSQL答案，但似乎不适用于Redshift:

I have already tried the common PostgreSQL answer, but seems like it doesn't work with Redshift:

SELECT  * FROM VALUES (1) AS q (col1);

ERROR: 42883: function values(integer) does not exist

我需要这个，因为某些原因我不能使用UNION ALL.任何帮助将不胜感激.

I need this because for some reason I can't use UNION ALL. Any help will be greatly appreciated.

推荐答案

正确的Postgres语法为:

The correct Postgres syntax would be:

SELECT * FROM (VALUES (1)) AS q (col1);

缺少一组括号.
但是似乎Redshift甚至不支持INSERT之外的VALUES表达式(就像现代的Postgres一样).因此，对于单行:

A set of parentheses was missing.
But it seems Redshift does not even support a VALUES expression outside of INSERT (like modern Postgres does). So, for a single row:

SELECT * FROM (SELECT 1) AS q (col1);

对于多行(不使用要求的UNION ALL)，您可以使用临时表.注意(每个文档):

For multiple rows (without using UNION ALL like requested) you can use a temporary table. Note (per documentation):

在会话结束时会自动删除一个临时表 是在其中创建的.

A temporary table is automatically dropped at the end of the session in which it was created.

CREATE TEMP TABLE q(col1 int);
INSERT INTO q(col1)
VALUES (1), (2), (3);

SELECT  * FROM q;

如果可以选择UNION ALL:

SELECT 1 AS col1
UNION ALL SELECT 2
UNION ALL SELECT 3;

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