# mybatis学习笔记(18)-mybatis逆向工程

标签: mybatis


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mybaits需要程序员自己编写sql语句,mybatis官方提供逆向工程,可以针对单表自动生成mybatis执行所需要的代码(mapper.java,mapper.xml、po..)

企业实际开发中,常用的逆向工程方式:由数据库的表生成java代码。

先附上官网链接:

下载逆向工程

这里其实可以添加Maven依赖的,因为跟着视频做的,所以我就建了个普通工程,直接添加了个lib文件夹,把要用的jar包直接copy进来了。

maven中央仓库MyBatis-Generator下载地址:【MyBatis Generator Core】

使用方法

运行逆向工程

根据官网说的(Running MyBatis Generator)

Running MyBatis Generator

MyBatis Generator (MBG) can be run in the following ways:

还可以通过eclipse的插件生成代码

建议使用java程序方式,不依赖开发工具。

生成代码配置文件

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE generatorConfiguration
  PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
  "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">

<generatorConfiguration>
    <context id="testTables" targetRuntime="MyBatis3">
        <commentGenerator>
            <!-- 是否去除自动生成的注释 true:是 : false:否 -->
            <property name="suppressAllComments" value="true" />
        </commentGenerator>
        <!--数据库连接的信息:驱动类、连接地址、用户名、密码 -->
        <jdbcConnection driverClass="com.mysql.jdbc.Driver"
            connectionURL="jdbc:mysql://120.25.162.238:3306/mybatis001?characterEncoding=utf-8" 
            userId="root"
            password="123">
        </jdbcConnection>
        <!-- <jdbcConnection driverClass="oracle.jdbc.OracleDriver"
            connectionURL="jdbc:oracle:thin:@127.0.0.1:1521:yycg" 
            userId="yycg"
            password="yycg">
        </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.iot.ssm.po"
            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" />
        </javaModelGenerator>
        <!-- targetProject:mapper映射文件生成的位置 -->
        <sqlMapGenerator targetPackage="com.iot.ssm.mapper" 
            targetProject=".\src">
            <!-- enableSubPackages:是否让schema作为包的后缀 -->
            <property name="enableSubPackages" value="false" />
        </sqlMapGenerator>
        <!-- targetPackage:mapper接口生成的位置 -->
        <javaClientGenerator type="XMLMAPPER"
            targetPackage="com.iot.ssm.mapper" 
            targetProject=".\src">
            <!-- enableSubPackages:是否让schema作为包的后缀 -->
            <property name="enableSubPackages" value="false" />
        </javaClientGenerator>
        <!-- 指定数据库表 -->
        <table tableName="items"></table>
        <table tableName="orders"></table>
        <table tableName="orderdetail"></table>
        <table tableName="user"></table>
        <!-- <table schema="" tableName="sys_user"></table>
        <table schema="" tableName="sys_role"></table>
        <table schema="" tableName="sys_permission"></table>
        <table schema="" tableName="sys_user_role"></table>
        <table schema="" tableName="sys_role_permission"></table> -->

        <!-- 有些表的字段需要指定java类型
         <table schema="" tableName="">
            <columnOverride column="" javaType="" />
        </table> -->
    </context>
</generatorConfiguration>

需要注意的位置:

执行生成程序

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);

} 

日志输出:

2016-02-27 16:29:46,419 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Retrieving column information for table "items"
2016-02-27 16:29:46,477 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "id", data type 4, in table "mybatis001..items"
2016-02-27 16:29:46,477 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "name", data type 12, in table "mybatis001..items"
2016-02-27 16:29:46,477 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "price", data type 7, in table "mybatis001..items"
2016-02-27 16:29:46,477 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "detail", data type -1, in table "mybatis001..items"
2016-02-27 16:29:46,477 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "pic", data type 12, in table "mybatis001..items"
2016-02-27 16:29:46,478 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "createtime", data type 93, in table "mybatis001..items"
2016-02-27 16:29:46,503 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Retrieving column information for table "orders"
2016-02-27 16:29:46,551 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "id", data type 4, in table "mybatis001..orders"
2016-02-27 16:29:46,551 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "user_id", data type 4, in table "mybatis001..orders"
2016-02-27 16:29:46,551 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "number", data type 12, in table "mybatis001..orders"
2016-02-27 16:29:46,551 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "createtime", data type 93, in table "mybatis001..orders"
2016-02-27 16:29:46,551 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "note", data type 12, in table "mybatis001..orders"
2016-02-27 16:29:46,577 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Retrieving column information for table "orderdetail"
2016-02-27 16:29:46,630 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "id", data type 4, in table "mybatis001..orderdetail"
2016-02-27 16:29:46,630 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "orders_id", data type 4, in table "mybatis001..orderdetail"
2016-02-27 16:29:46,631 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "items_id", data type 4, in table "mybatis001..orderdetail"
2016-02-27 16:29:46,631 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "items_num", data type 4, in table "mybatis001..orderdetail"
2016-02-27 16:29:46,656 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Retrieving column information for table "user"
2016-02-27 16:29:46,706 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "id", data type 4, in table "mybatis001..user"
2016-02-27 16:29:46,706 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "username", data type 12, in table "mybatis001..user"
2016-02-27 16:29:46,706 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "birthday", data type 91, in table "mybatis001..user"
2016-02-27 16:29:46,706 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "sex", data type 1, in table "mybatis001..user"
2016-02-27 16:29:46,706 [main] DEBUG [org.mybatis.generator.internal.db.DatabaseIntrospector] - Found column "address", data type 12, in table "mybatis001..user"

生成后的代码:

逆向工程

使用生成的代码

需要将生成工程中所生成的代码拷贝到自己的工程中。

测试ItemsMapper中的方法

package com.iot.ssm.mapper;

import static org.junit.Assert.*;

import java.util.Date;
import java.util.List;

import com.iot.ssm.po.Items;
import com.iot.ssm.po.ItemsExample;
import org.junit.Before;
import org.junit.Test;
import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;


public class ItemsMapperTest {

    private ApplicationContext applicationContext;

    private ItemsMapper itemsMapper;

    //在setUp这个方法得到spring容器
    @Before
    public void setUp() throws Exception {
        applicationContext = new ClassPathXmlApplicationContext("classpath:spring/applicationContext.xml");
        itemsMapper = (ItemsMapper) applicationContext.getBean("itemsMapper");
    }

    //根据主键删除 
    @Test
    public void testDeleteByPrimaryKey() {

    }

    //插入
    @Test
    public void testInsert() {
        //构造 items对象
        Items items = new Items();
        items.setName("手机");
        items.setPrice(999f);
        items.setCreatetime(new Date());
        itemsMapper.insert(items);
    }

    //自定义条件查询
    @Test
    public void testSelectByExample() {
        ItemsExample itemsExample = new ItemsExample();
        //通过criteria构造查询条件
        ItemsExample.Criteria criteria = itemsExample.createCriteria();
        criteria.andNameEqualTo("笔记本");
        //可能返回多条记录
        List<Items> list = itemsMapper.selectByExample(itemsExample);

        System.out.println(list);

    }

    //根据主键查询
    @Test
    public void testSelectByPrimaryKey() {
        Items items = itemsMapper.selectByPrimaryKey(1);
        System.out.println(items);
    }

    //更新数据
    @Test
    public void testUpdateByPrimaryKey() {

        //对所有字段进行更新,需要先查询出来再更新
        Items items = itemsMapper.selectByPrimaryKey(1);

        items.setName("手机");

        itemsMapper.updateByPrimaryKey(items);
        //如果传入字段不空为才更新,在批量更新中使用此方法,不需要先查询再更新
        //itemsMapper.updateByPrimaryKeySelective(record);

    }

}

作者@brianway更多文章:个人网站 | CSDN | oschina