如何在 MySQL 表中显示 3 个随机值?
对于随机,使用 RAND();而对于数值,例如此处为 3,使用 LIMIT 3 −
select yourColumnName from yourTableName order by rand() limit 3;
首先让我们创建一个表 −
mysql> create table DemoTable646 ( Id int NOT NULL AUTO_INCREMENT PRIMARY KEY,FirstName varchar(100) ); Query OK, 0 rows affected (0.76 sec)
使用 insert 命令在表中插入一些记录 −
mysql> insert into DemoTable646(FirstName) values('John'); Query OK, 1 row affected (0.18 sec) mysql> insert into DemoTable646(FirstName) values('Bob'); Query OK, 1 row affected (0.14 sec) mysql> insert into DemoTable646(FirstName) values('Chris'); Query OK, 1 row affected (0.10 sec) mysql> insert into DemoTable646(FirstName) values('David'); Query OK, 1 row affected (0.28 sec) mysql> insert into DemoTable646(FirstName) values('Bob'); Query OK, 1 row affected (0.11 sec) mysql> insert into DemoTable646(FirstName) values('Carol'); Query OK, 1 row affected (0.27 sec) mysql> insert into DemoTable646(FirstName) values('Mike'); Query OK, 1 row affected (0.10 sec)
使用 select 语句从表中显示所有记录 −
mysql> select *from DemoTable646;
这将产生以下输出 −
+----+-----------+ | Id | FirstName | +----+-----------+ | 1 | John | | 2 | Bob | | 3 | Chris | | 4 | David | | 5 | Bob | | 6 | Carol | | 7 | Mike | +----+-----------+ 7 rows in set (0.00 sec)
以下是可以从 MySQL 表中显示 3 个随机值:−
mysql> select FirstName from DemoTable646 order by rand() limit 3;
这将产生以下输出 −
+-----------+ | FirstName | +-----------+ | Mike | | John | | Chris | +-----------+ 3 rows in set (0.00 sec)
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