在postgres中拼合嵌套记录

Question

如何拼合外部select（在PostgreSQL中）的foo列？

WITH RECURSIVE t AS (
    SELECT row(d.*) as foo FROM some_multicolumn_table as d 
UNION ALL 
    SELECT foo FROM t WHERE random() < .5 
) 
SELECT foo FROM t 

我要的是输出所有列（水平，即作为多列的行）在外部选择，而不仅仅是一个单一的“记录”栏。

如何做到这一点？

Answer 1

你不需要ROW构造存在，所以你可以通过使用(foo).*扩大纪录：

WITH RECURSIVE t AS (
    SELECT d as foo FROM some_multicolumn_table as d 
UNION ALL 
    SELECT foo FROM t WHERE random() < .5 
) 
SELECT (foo).* FROM t; 

虽然写此查询可能是简单的：

WITH RECURSIVE t AS (
    SELECT d.* FROM some_multicolumn_table as d 
UNION ALL 
    SELECT t.* FROM t WHERE random() < .5 
) 
SELECT * FROM t; 

我建议尽量保持简单。但我认为这仅仅是一个例证。