如何缩进输出以使国家缩进2个空格？

Question

这是向我返回左栏中区域ID的输出，右栏中的region_name以及属于该区域的国家但我想让国家缩进几个空格的查询。

SELECT region_id, region_name
FROM
(
    SELECT r.region_id, r.region_name, 0 AS ent
    FROM regions r

    UNION ALL

    SELECT r.region_id, c.country_name, 1 AS ent
    FROM regions r
    INNER JOIN countries c
        ON r.region_id = c.region_id
)
ORDER BY region_id, ent, region_name;

1   Europe
1   Belgium
1   Denmark
1   France
1   Germany
1   Italy
1   Netherlands
1   Switzerland
1   United Kingdom
2   Americas
2   Argentina
2   Brazil
2   Canada
2   Mexico
2   United States of America

Answer 1

这应该有效：

SELECT r.region_id, CONCAT('  ', c.country_name), 1 AS ent

您可能需要为组合字段添加AS子句以将它们组合在一起。