使用随机值列在 MySQL 中随机排序?
mysqlmysqli database更新于 2023/12/6 12:41:00
我们先创建一个表。然后我们将创建一个新的随机值列并随机排序记录:
mysql> create table DemoTable ( StudentId int NOT NULL AUTO_INCREMENT PRIMARY KEY, StudentName varchar(20) ); Query OK, 0 rows affected (0.57 sec)
下面是使用 insert 命令在表中插入一些记录的查询:
mysql> insert into DemoTable(StudentName) values('Larry');
Query OK, 1 row affected (0.20 sec)
mysql> insert into DemoTable(StudentName) values('Sam');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable(StudentName) values('Mike');
Query OK, 1 row affected (0.34 sec)
mysql> insert into DemoTable(StudentName) values('Carol');
Query OK, 1 row affected (0.13 sec)
mysql> insert into DemoTable(StudentName) values('Robert');
Query OK, 1 row affected (0.14 sec)
mysql> insert into DemoTable(StudentName) values('Chris');
Query OK, 1 row affected (0.14 sec)
以下是使用 select 语句显示表中记录的查询:
mysql> select *from DemoTable;
这将产生以下输出 −
+-----------+-------------+ | StudentId | StudentName | +-----------+-------------+ | 1 | Larry | | 2 | Sam | | 3 | Mike | | 4 | Carol | | 5 | Robert | | 6 | Chris | +-----------+-------------+ 6 rows in set (0.00 sec)
这是按随机字段排序的查询。我们在这里创建了一个新的随机字段:
mysql> SELECT * FROM (SELECT StudentName, RAND()+1 AS randomRecord FROM DemoTable ) tbl ORDER BY RandomRecord DESC;
这将产生以下输出 −
+-------------+--------------------+ | StudentName | RandomRecord | +-------------+--------------------+ | Carol | 1.8973721451101566 | | Chris | 1.7821308670399065 | | Mike | 1.4640037673190271 | | Larry | 1.4134691557041081 | | Sam | 1.1408822407395414 | | Robert | 1.0948494543273461 | +-------------+--------------------+ 6 rows in set (0.00 sec)
