一、逆向工程
1.1、概述
mybatis需要程序号自己编写的SQL。
mybatis官方提供了逆向工程，可以针对单表自动生成mybatis执行所需要的代码
（mapper,java,maper.xml,po...)
一般都是由数据库到java代码， 的生成过程
二、导入jar包
2.1、mybatis-generator
三、配置xml
3.1、generatorConfig.xml
<?xml version="1.0" encoding="UTF-8"?><!DOCTYPE generatorConfigurationPUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN""http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd"><generatorConfiguration> <!--指定数据库jar包 --> <classPathEntry location="G:/jar/mysql-connector-java-5.1.37-bin.jar" /> <context id="DB2Tables" targetRuntime="MyBatis3"> <commentGenerator> <!-- 是否去除自动生成的注释 true：是 ： false:否 --> <property name="suppressAllComments" value="true" /> </commentGenerator> <!--JDBC连接配置，driver,url,user,password --> <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/mybatis?character=utf8" userId="root" password="root"> </jdbcConnection> <!--默认false，把JDBC DECIMAL 和 NUMERIC 类型解析为 Integer，为 true时把JDBC DECIMAL 和 NUMERIC 类型解析为java.math.BigDecimal --> <javaTypeResolver> <property name="forceBigDecimals" value="false" /> </javaTypeResolver> <!-- targetProject:生成PO类的位置 --> <javaModelGenerator targetPackage="com.mybatis.po" targetProject=".\src"> <property name="enableSubPackages" value="false" /> <property name="trimStrings" value="true" /> </javaModelGenerator> <!-- targetProject:mapper映射文件生成的位置 --> <sqlMapGenerator targetPackage="com.pb.mybatis.mapping" targetProject=".\src"> <!-- enableSubPackages:是否让schema作为包的后缀 --> <property name="enableSubPackages" value="false" /> <!-- 从数据库返回的值被清理前后的空格 --> <property name="trimStrings" value="true" /> </sqlMapGenerator> <!-- targetPackage：mapper接口生成的位置 --> <javaClientGenerator type="XMLMAPPER" targetPackage="com.pb.mybatis.mapper" targetProject=".\src"> <!-- enableSubPackages:是否让schema作为包的后缀 --> <property name="enableSubPackages" value="false" /> </javaClientGenerator> <!--指定要生成的表 --> <table tableName="author"></table> <table tableName="blog"></table> <table tableName="posts"></table> </context></generatorConfiguration>
四、运行java程序生成
4.1、java程序
import java.io.File;import java.io.IOException;import java.util.ArrayList;import java.util.List;import org.mybatis.generator.api.MyBatisGenerator;import org.mybatis.generator.config.Configuration;import org.mybatis.generator.config.xml.ConfigurationParser;import org.mybatis.generator.exception.XMLParserException;import org.mybatis.generator.internal.DefaultShellCallback;public class GeneratorSqlmap { public void generator() throws Exception{ List<String> warnings = new ArrayList<String>(); boolean overwrite = true; //指定 逆向工程配置文件 File configFile = new File("generatorConfig.xml"); ConfigurationParser cp = new ConfigurationParser(warnings); Configuration config = cp.parseConfiguration(configFile); DefaultShellCallback callback = new DefaultShellCallback(overwrite); MyBatisGenerator myBatisGenerator = new MyBatisGenerator(config, callback, warnings); myBatisGenerator.generate(null); } public static void main(String[] args) throws Exception { try { GeneratorSqlmap generatorSqlmap = new GeneratorSqlmap(); generatorSqlmap.generator(); } catch (Exception e) { e.printStackTrace(); } }}
五、测试
5.1、测试类
package com.pb.ssm.mapper;import static org.junit.Assert.fail;import java.util.Date;import java.util.List;import javax.crypto.Cipher;import org.junit.Before;import org.junit.Test;import org.springframework.context.ApplicationContext;import org.springframework.context.support.ClassPathXmlApplicationContext;import com.pb.ssm.po.Author;import com.pb.ssm.po.AuthorExample;import com.pb.ssm.po.AuthorExample.Criteria;public class AuthorMapperTest { private ApplicationContext applicationContext; private AuthorMapper authorMapper; @Before public void setUp() throws Exception { applicationContext=new ClassPathXmlApplicationContext("ApplicationContext.xml"); authorMapper=(AuthorMapper) applicationContext.getBean("authorMapper"); } //根据条件查询记录数 @Test public void testCountByExample() { AuthorExample example=new AuthorExample(); //可以加条件，不加条件默认查询全部 Criteria criteria=example.createCriteria(); //加条件，介绍不是空的 criteria.andAuthorBioIsNotNull(); int num=authorMapper.countByExample(example); System.out.println("num="+num); } //根据条件删除 @Test public void testDeleteByExample() { AuthorExample example=new AuthorExample(); //可以加条件，不加条件默认查询全部 Criteria criteria=example.createCriteria(); criteria.andAuthorUsernameEqualTo("程序员"); int num=authorMapper.deleteByExample(example); System.out.println("num="+num); } //根据主键ID删除 @Test public void testDeleteByPrimaryKey() { int num=authorMapper.deleteByPrimaryKey(18); System.out.println("num="+num); } //插入 @Test public void testInsert() { Author author=new Author(); author.setAuthorUsername("再测试一下"); author.setAuthorPassword("admin123"); author.setAuthorEmail("admin1234@qq.com"); int num=authorMapper.insert(author); System.out.println("num="+num); //这个方法插入，默认不会把数据库自增加ID返回，如果需要，可以手动增加 System.out.println("插入后的ID"+author.getAuthorId()); } //插入 @Test public void testInsertSelective() { Author author=new Author(); author.setAuthorUsername("再测试一下"); author.setAuthorPassword("admin123"); author.setAuthorEmail("admin1234@qq.com"); author.setRegisterTime(new Date()); int num=authorMapper.insert(author); System.out.println("num="+num); //这个方法插入，默认不会把数据库自增加ID返回，如果需要，可以手动增加 System.out.println("插入后的ID"+author.getAuthorId()); } //自定义 条件查询 @Test public void testSelectByExample() { //声明一个对象 AuthorExample authorExample=new AuthorExample(); //创建criteria对象添加条件 and 连接 Criteria criteria=authorExample.createCriteria(); //需要手动加% criteria.andAuthorUsernameLike("%张三%"); List<Author> list=authorMapper.selectByExample(authorExample); System.out.println(list.size()); } //根据主键ID查询 @Test public void testSelectByPrimaryKey() { Author author= authorMapper.selectByPrimaryKey(6); System.out.println(author.getAuthorUsername()+"..."+author.getAuthorBio()); } @Test public void testUpdateByExampleSelective() { fail("Not yet implemented"); } @Test public void testUpdateByExample() { fail("Not yet implemented"); } @Test public void testUpdateByPrimaryKeySelective() { fail("Not yet implemented"); } @Test public void testUpdateByPrimaryKey() { fail("Not yet implemented"); }}