Question

为什么我不能运行这个MySQL命令？

SELECT *
FROM users
WHERE
    id = 1 OR
    id BETWEEN 2 AND 8
GROUP BY
    username ASC
ORDER BY
    username ASC
LIMIT 5

任何人都可以解释一下吗？

我收到以下错误：

ERROR 1064 (42000): You have an error in your SQL syntax;
check the manual that corresponds to your MySQL server version for the right
syntax to use near '= 1 OR id BETWEEN 2 AND 8 GROUP BY username ASC
ORDER BY username ASC LIMIT 5' at line 1

Answer 1

您缺少browse.showOpenDialog(MainForm.frame)条款：

WHERE

您收到的错误是因为SELECT * FROM users WHERE id = 1 OR id BETWEEN 2 AND 8 GROUP BY username ASC ORDER BY username ASC LIMIT 5;被视为id的别名而MySQL正在期待类似users，,，[LEFT, RIGHT, INNER, CROSS] JOIN的内容，WHERE，GROUP BY或ORDER BY。

LIMIT在MySQL（至少大多数版本）中是多余的，因为ORDER BY中的ASC进行排序（请参阅documentation）。但是，我不会依赖于此，并使用：

GROUP BY

Answer 2

只需在条件之前添加where，也可以在群组之后删除ASC，这是没有意义的：

SELECT * FROM users where id = 1 
OR id BETWEEN 2 AND 8 
GROUP BY user
ORDER BY user ASC LIMIT 5

MySQL命令中的双ASC

2 个答案: