坏味道--Switch声明(Switch Statements) 特征 你有一个复杂的 switch 语句或 if 序列语句. 问题原因 面向对象程序的一个最明显特征就是:少用 switch  和 case 语句.从本质上说,switch 语句的问题在于重复(if 序列也同样如此).你常会发现 switch 语句散布于不同地点.如果要为它添加一个新的 case 子句,就必须找到所有 switch 语句并修改它们.面向对象中的多态概念可为此带来优雅的解决办法. 大多数时候,一看到 switch 语…

开启 binary logs 功能 在 mysql 配置文件中配置 log-bin,重启 mysql my.cnf (on Linux/unix) or my.ini (on Windows) 例子: [client] ... [mysqld] ... log-bin=mysql-bin (log_bin=/var/mydb/bin-log,指定 log 的路径,以及名称前缀) --- 一旦重启,Mysql 会自动创建新的二进制文件.您也不妨看看下面的变量: server-id = 1 expi…

Mapped Statements collection does not contain value for后面是什么类什么方法之类的: 错误原因有几种: 1.mapper.xml中没有加入namespace 2.mapper.xml中的方法和接口mapper的方法不对应 3.mapper.xml没有加入到mybatis-config.xml中(即总的配置文件),例外:配置了mapper文件的包路径的除外 4.mapper.xml文件名和所写的mapper名称不相同.…

http://www.mysqltutorial.org/mysql-signal-resignal/ Summary: in this tutorial, you will learn how to use SIGNAL  and RESIGNAL  statements to raise error conditions inside stored procedures. MySQL SIGNAL statement You use the SIGNAL  statement to retu…

首页 > 精品文库 > mybatis报错Mapped Statements collection does not contain value for com.inter.IOper mybatis报错Mapped Statements collection does not contain value for com.inter.IOper 2015-04-09 浏览(52)   [摘要:正在顺序挪用IOperation接心中的getAllItems方式时,涌现了以下毛病: Excepti…

COMPUTER ORGANIZATION AND ARCHITECTURE DESIGNING FOR PERFORMANCE NINTH EDITION A  variety  of  studies  have  been  made  to  analyze  the  behavior  of  HLL  programs. Table  4.8,  discussed  in  Chapter  4,  includes  key  results  from  a  number …

Both parameterized queries and prepared statements are exactly the same thing. Prepared statement seems to be the more commonly used term, but there is no difference between both terms. Parameterized queries and prepared statements are features of da…

编译通过并且运行web成功后,访问的页面不需要连接数据库,不牵扯到反射调用实体类就不会报错, 报错内容如下: [WARNING] org.springframework.web.util.NestedServletException: Request processing failed; nested exception is org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exce…

问题: org.mybatis.spring.MyBatisSystemException: nested exception is org.apache.ibatis.exceptions.PersistenceException: ### Error updating database. Cause: java.lang.IllegalArgumentException: Mapped Statements collection does not contain value for com.…

http://dev.mysql.com/doc/refman/5.7/en/prepare.html Statement names are not case sensitive. preparable_stmt is either a string literal or a user variable that contains the text of the SQL statement. The text must represent a single statement, not mul…