mysql - 是否可以执行 ORDER BY RAND() LIMIT 但包含 header ？

Question

是否可以从 user 表中返回随机选择的行并将标题作为第一行？我现在的 SQL 仅返回 5 个随机行(不一定是 header )

SELECT
    'id',
    'name'
UNION ALL SELECT
    id,
    name

INTO OUTFILE 'example.txt'
    FIELDS TERMINATED BY ' , ' ENCLOSED BY '"' ESCAPED BY '\\' LINES TERMINATED BY '\r\n'

FROM
    users

ORDER BY RAND() LIMIT 5

Answer 1

试试这个

SELECT 'id','name'
UNION ALL 
Select a.* from(
    SELECT id, name
    FROM  users
    ORDER BY RAND() LIMIT 5
 )a
INTO OUTFILE 'example.txt'  FIELDS TERMINATED BY ','  ENCLOSED BY '"' ESCAPED BY '\\' LINES TERMINATED BY '\r\n';