Question

我想在表中插入一些值，然后剩余的值应该来自Postgres中的select子查询，我被困住了，我还需要在其他地方重用代码请帮帮我。我遇到了subquery must return only one column错误。我想返回三列电子邮件，姓名，地址

INSERT INTO
    books
      VALUES 
      ( 1, 2, 3, (SELECT email, name, address FROM users WHERE userID=1)) RETURNING *;

Answer 1

如果您的INSERT源是SELECT，请不要使用VALUES子句：

INSERT INTO books
SELECT 1,2,3,email, name, address 
FROM users 
WHERE userID=1
RETURNING *;

请注意，明确列出目标表的列是一种很好的编码风格：insert into books (col1, col2, col3, ...)

Answer 2

SELECT `email` as f FROM users WHERE userID=1
union SELECT `name` as f FROM users WHERE userID=1
union SELECT `address` as f FROM users WHERE userID=1

如何使用select子查询返回多个列来执行插入选择

2 个答案: