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[Java教程]MyBatis入门(七)


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.

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

3.1、generatorConfig.

 

<??><!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="      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.import org.mybatis.generator.exception.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.);     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.ClassPathimport 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 ClassPath);    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");  }}