mysql、sqlserver的order by按字段内容排序

一、mysql、sqlserver都适用的方法

SELECT username,(CASE WHEN username = '用户1' THEN 1
    WHEN username = '用户2' THEN 2
    WHEN username = '用户3' THEN 3 
    WHEN username = '用户4' THEN 4
    WHEN username = '用户5' THEN 5
    WHEN username = '用户6' THEN 6 ELSE 7 END) orderUsername
FROM sharingcar_info
ORDER BY orderUsername

二、mysql第二种方法

SELECT username
FROM sharingcar_info
ORDER BY username='用户1' DESC,username='用户2' DESC,
username='用户3' DESC,username='用户4' DESC,
username='用户5' DESC,username='用户6' DESC