mybatis逆向工程

mybatis逆向工程

標籤： mybatis

---

---

mybaits需要程序員自己編寫sql語句,mybatis官方提供逆向工程,可以針對單表自動生成mybatis執行所需要的代碼（mapper.Java,mapper.xml、po..）

企業實際開發中，常用的逆向工程方式：由數據庫的表生成java代碼。

先附上官網鏈接：

• MyBatis Generator
• A code generator for MyBatis and iBATIS. - GitHub

下載逆向工程

這裏其實可以添加Maven依賴的，因爲跟着視頻做的，所以我就建了個普通工程，直接添加了個lib文件夾，把要用的jar包直接copy進來了。

maven中央倉庫MyBatis-Generator下載地址：【MyBatis Generator Core】

使用方法

運行逆向工程

根據官網說的（Running MyBatis Generator）：

Running MyBatis Generator

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

• From the command prompt with an XML configuration
• As an Ant task with an XML configuration
• As a Maven Plugin
• From another Java program with an XML configuration
• From another Java program with a Java based configuration

還可以通過eclipse的插件生成代碼

建議使用java程序方式，不依賴開發工具。

生成代碼配置文件

<?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>
            <!-- 是否去除自動生成的註釋 true：是 ： false:否 -->
            <property name="suppressAllComments" value="true" />
        </commentGenerator>
        <!--數據庫連接的信息：驅動類、連接地址、用戶名、密碼 -->
        <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> -->

        <!-- 默認false，把JDBC DECIMAL 和 NUMERIC 類型解析爲 Integer，爲 true時把JDBC DECIMAL 和 
            NUMERIC 類型解析爲java.math.BigDecimal -->
        <javaTypeResolver>
            <property name="forceBigDecimals" value="false" />
        </javaTypeResolver>

        <!-- targetProject:生成PO類的位置 -->
        <javaModelGenerator targetPackage="com.iot.ssm.po"
            targetProject=".\src">
            <!-- enableSubPackages:是否讓schema作爲包的後綴 -->
            <property name="enableSubPackages" value="false" />
            <!-- 從數據庫返回的值被清理前後的空格 -->
            <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:是否讓schema作爲包的後綴 -->
            <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:是否讓schema作爲包的後綴 -->
            <property name="enableSubPackages" value="false" />
        </javaClientGenerator>
        <!-- 指定數據庫表 -->
        <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類型
         <table schema="" tableName="">
            <columnOverride column="" javaType="" />
        </table> -->
    </context>
</generatorConfiguration>

需要注意的位置：

• javaModelGenerator,生成PO類的位置
• sqlMapGenerator,mapper映射文件生成的位置
• javaClientGenerator,mapper接口生成的位置
• table,指定數據庫表

執行生成程序

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);

} 

日誌輸出：

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"

生成後的代碼：

使用生成的代碼

需要將生成工程中所生成的代碼拷貝到自己的工程中。

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

    //根據主鍵刪除 
    @Test
    public void testDeleteByPrimaryKey() {

    }

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

    //自定義條件查詢
    @Test
    public void testSelectByExample() {
        ItemsExample itemsExample = new ItemsExample();
        //通過criteria構造查詢條件
        ItemsExample.Criteria criteria = itemsExample.createCriteria();
        criteria.andNameEqualTo("筆記本");
        //可能返回多條記錄
        List<Items> list = itemsMapper.selectByExample(itemsExample);

        System.out.println(list);

    }

    //根據主鍵查詢
    @Test
    public void testSelectByPrimaryKey() {
        Items items = itemsMapper.selectByPrimaryKey(1);
        System.out.println(items);
    }

    //更新數據
    @Test
    public void testUpdateByPrimaryKey() {

        //對所有字段進行更新，需要先查詢出來再更新
        Items items = itemsMapper.selectByPrimaryKey(1);

        items.setName("手機");

        itemsMapper.updateByPrimaryKey(items);
        //如果傳入字段不空爲才更新，在批量更新中使用此方法，不需要先查詢再更新
        //itemsMapper.updateByPrimaryKeySelective(record);

    }

}