1.SQL Server:
SELECT TOP n * FROM tableName ORDER BY NEWID();
2.ORACLE:
SELECT * FROM (SELECT * FROM tableNameORDER BY DBMS_RANDOM.RANDOM()) WHERE RONUM <= n
3.MySQL:
SELECT * FROM...
四种<em>数据</em>库<em>随机</em>获取10<em>条</em><em>数据</em>的方法
SQL Server:
复制代码代码如下:
SELECT TOP 10 * FROM T_USER ORDER BY NEWID()
ORACLE:
复制代码代码如下:
SELECT * FROM (SELECT * FROM T_USER ORDER BY DBMS_RANDOM.RANDOM()) WHER
Hibernate执行的话效率太低，我<em>数据</em>库才3000<em>条</em>左右，就用了5秒时间。
建议用jdbc执行
[code="java"]finder = new Finder("")
.append(" FROM Event21 ORDER BY RAND() ");
int size = find(finder).size();
Random r = new Random();
...
从<em>数据</em>库获取 10 <em>条</em><em>随机</em><em>数据</em>SQL Server:SELECT TOP 10 * FROM T_USER ORDER BY NEWID();Oracle:SELECT * FROM (SELECT * FROM T_USER ORDER BY DBMS_RANDOM.RANDOM()) WHERE RONUM <= 10;MySQL:从 MySQL <em>随机</em>选取<em>数据</em>最简单的办法就是使用 ”ORDER
org.<em>hibernate</em>.TypeMismatchException: Provided id of the wrong type for class com.itheima.domain.Customer. Expected: class java.lang.Long, got class java.lang.Integer
at org.<em>hibernate</em>.event.interna...
select top 1 * from table order by newid()这个方法只适用sql server
SELECT top1 * FROM 表 ORDER BY Rnd(id) 这句适用于ACCESS的
转载于:https://www.cnblogs.com/master-zhu/archive/2009/09/01/1558112.html...
介绍@Query注释之前，先看看怎么利用@NamedQuery进行命名查询1.现在实体类上定义方法已经具体查询语句@Entity
@NamedQuery(name = "Task.findByTaskName",
query = "select t from Task t where t.taskName = ?1")
public class Task{}2.然后我们继承接口之后，就可以直接用
public static void main(String[] args){ String[] b = {"公共的", "私有的", "受保护的"}; Random rand = new Random(); int num = rand.nextInt(3); System.out.println(b[num]); }
1、"SELECT * FROM table ORDER BY RAND() LIMIT n";
2、"SELECT *, myrand as RAND() FROM table ORDER BY myrand LIMIT n";
3、"SELECT * FROM table WHERE id >= ((SELECT MAX(id) FROM
table)-(SELECT MIN(id)
mysql<em>随机</em>获取一<em>条</em>或者多<em>条</em><em>数据</em>
原文地址：http://www.im286.com/thread-7091552-1-1.html
转来备份
研究一些<em>随机</em>的因素，主要是讲究效率问题。
语句一：
select * from users order by rand() LIMIT 1
MYSQL手册<em>里</em>面针对RAND()的提示大概意思就是，在 ORDER BY从句<em>里</em>面不能使用RAND()...
