如何编写一个从数据库中随机选择9行的查询？

Question

SELECT * FROM tbl_specialisation
     WHERE LENGTH(spec_specialise) < 20 ORDER BY spec_specialise LIMIT 9 

添加到此查询

Answer 1

USE ORDER BY RAND()

$sql= "SELECT * FROM `tbl_specialisation`WHERE LENGTH(spec_specialise) < 20 ORDER BY RAND() LIMIT 9 ";

Answer 2

您的问题不明确，因为您要求9个随机字段，但在SQL查询中，您尝试获取9条记录。如果您想从表中获得9条记录，请使用以下内容。

$sql= "SELECT * FROM `tbl_specialisation`WHERE LENGTH(spec_specialise) < 20 ORDER BY RAND() LIMIT 9 ";  

Answer 3

“SELECT * FROM tbl_specialisation WHERE LENGTH（spec_specialise）＆lt; 20 ORDER BY RAND（）LIMIT 9”;