- MyBatis的前身就是著名的Ibatis,不知何故脱离了Apache改名为MyBatis。
MyBatis所说是轻量级的ORM框架,在网上看过一个测试报告,感觉相比于Hibernate来说,优势并不明显。
session = sessionFactory.openSession(); // 用于普通update session = sessionFactory.openSession(ExecutorType.BATCH, true ); // 用于批量update
1 < insert id ="insert" parameterType ="sdc.mybatis.test.Student" > 2 <!-- WARNING - @mbggenerated This element is automatically generated by 3 MyBatis Generator, do not modify. This element was generated on Mon May 09 4 11:09:37 CST 2011. --> 5 insert into student (id, name, sex, 6 address, telephone, t_id 7 ) 8 values (#{id,jdbcType=INTEGER}, #{name,jdbcType=VARCHAR}, 9 #{sex,jdbcType=VARCHAR}, 10 #{address,jdbcType=VARCHAR}, #{telephone,jdbcType=VARCHAR}, #{tId,jdbcType=INTEGER} 11 ) 12 </ insert >
- 我不清楚原因在哪里, 就配置了MyBatis的log4j,想查看下日志。下载了log4j.jar和commons-logging.jar并配置到项目的类路径,然后在代码路径下新建文件log4j.properties,内容如下:
log4j.rootLogger=DEBUG, stdout # SqlMap logging configuration... log4j.logger.com.ibatis=DEBUG log4j.logger.com.ibatis.common.jdbc.SimpleDataSource=DEBUG log4j.logger.com.ibatis.sqlmap.engine.cache.CacheModel=DEBUG log4j.logger.com.ibatis.sqlmap.engine.impl.SqlMapClientImpl=DEBUG log4j.logger.com.ibatis.sqlmap.engine.builder.xml.SqlMapParser=DEBUG log4j.logger.com.ibatis.common.util.StopWatch=DEBUG log4j.logger.java.sql.Connection=DEBUG log4j.logger.java.sql.Statement=DEBUG log4j.logger.java.sql.PreparedStatement=DEBUG log4j.logger.java.sql.ResultSet=DEBUG # Console output... log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%5p [%t] - %m%n
DEBUG [main] - Created connection 3502256 . DEBUG [main] - ooo Connection Opened DEBUG [main] - ==> Executing: insert into student ( name , sex , address , telephone , t_id ) values ( ? , ? , ? , ? , ? ) DEBUG [main] - ==> Parameters: 新人0 ( String ), male ( String ), addr0 ( String ), dd ( String ), 3 ( Integer ) DEBUG [main] - ==> Executing: insert into student ( name , sex , address , telephone , t_id ) values ( ? , ? , ? , ? , ? ) DEBUG [main] - ==> Parameters: 新人1 ( String ), male ( String ), ............... ............... DEBUG [main] - xxx Connection Closed DEBUG [main] - Returned connection 3502256 to pool . - 最后一点是关于数据库批量插入时sql语句级的优化,我特意测试了两种方式,在StudentMapper中配置了两种insert模式。第一种 对应insert value1,insert value2,,,,;第二种对应insert values (value1, value2,....)。发现后者果然比前者快很多啊。下面是两种insert模式,及测试结果对应图:
<!-- 在外部for循环调用一千次 --> < insert id ="insert" parameterType ="sdc.mybatis.test.Student" > insert into student (id, name, sex, address, telephone, t_id ) values (#{id,jdbcType=INTEGER}, #{name,jdbcType=VARCHAR}, #{sex,jdbcType=VARCHAR}, #{address,jdbcType=VARCHAR}, #{telephone,jdbcType=VARCHAR}, #{tId,jdbcType=INTEGER} ) </ insert > <!-- 批量 ,传入一个长度为1000的list --> < insert id ="insertBatch" > insert into student ( < include refid ="Base_Column_List" /> ) values < foreach collection ="list" item ="item" index ="index" separator ="," > (null,#{item.name},#{item.sex},#{item.address},#{item.telephone},#{item.tId}) </ foreach > </ insert >
附录:
- MyBatis配置文件的DTD文件(与Ibatis3不同):http://mybatis.org/dtd/
- MyBatis的中文手册:http://mybatis.googlecode.com/files/MyBatis%203%20User%20Guide%20Simplified%20Chinese.pdf