Mybatis-Generator的具体使用方法

Mybatis属于半自动ORM，在使用这个框架中，工作量最大的就是书写Mapping的映射文件，由于手动书写很容易出错，我们可以利用Mybatis-Generator来帮我们自动生成文件。
转自zorro的菜鸟笔记

1.相关文件

关于Mybatis-Generator的下载可以到这个地址https://github.com/mybatis/generator/releases进行下载

因为我使用的是mysql数据库，所以在这里，先准备一下mysql连接驱动的jar包

Screen Shot 2018-10-06 at 8.57.45 PM.png

这里还需要一个配置文件

generatorConfig.xml

<?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>
      <!--数据库驱动-->
     <classPathEntry    location="/xxx/xxx/Mybatis/mysql-connector-java-8.0.11.jar"/>
      <context id="DB2Tables"    targetRuntime="MyBatis3">
          <commentGenerator>
             <property name="suppressDate" value="true"/>
             <property name="suppressAllComments" value="true"/>
         </commentGenerator>
         <!--数据库链接地址账号密码-->
         <jdbcConnection driverClass="com.mysql.jdbc.Driver" connectionURL="jdbc:mysql://localhost:3306/mybatis" userId="root" password="root">
         </jdbcConnection>
         <javaTypeResolver>
             <property name="forceBigDecimals" value="false"/>
         </javaTypeResolver>
         <!--生成Model类存放位置-->
         <javaModelGenerator targetPackage="com.project.model" targetProject="src">
             <property name="enableSubPackages" value="true"/>
             <property name="trimStrings" value="true"/>
         </javaModelGenerator>
         <!--生成映射文件存放位置-->
         <sqlMapGenerator targetPackage="com.project.mapping" targetProject="src">
             <property name="enableSubPackages" value="true"/>
         </sqlMapGenerator>
         <!--生成Dao类存放位置-->
         <javaClientGenerator type="XMLMAPPER" targetPackage="com.project.dao" targetProject="src">
             <property name="enableSubPackages" value="true"/>
         </javaClientGenerator>
         <!--生成对应表及类名-->
         <table tableName="stationInfo" domainObjectName="Station" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>
     </context>
 </generatorConfiguration>

以上配置文件中的

<table tableName="stationInfo" domainObjectName="Station" enableCountByExample="false" enableUpdateByExample="false" enableDeleteByExample="false" enableSelectByExample="false" selectByExampleQueryId="false"></table>

tableName和domainObjectName为必选项，分别代表数据库表名和生成的实力类名，其余的可以自定义去选择（一般情况下均为false）

切换到项目目录下执行以下语句：

java -jar mybatis-generator-core-1.3.7.jar -configfile generatorConfig.xml -overwrite

执行命令完后，我们可以看到src多了几个目录，如图下所示：

Screen Shot 2018-10-06 at 9.11.39 PM.png

打开文件夹查看生成的代码

Station.java

package com.cugb.model;

public class Station {
    private Integer stationid;

    private String trannum;

    private String station;

    private String outtime;

    private Integer daytime;

    private Float siteprice;

    public Integer getStationid() {
        return stationid;
    }

    public void setStationid(Integer stationid) {
        this.stationid = stationid;
    }

    public String getTrannum() {
        return trannum;
    }

    public void setTrannum(String trannum) {
        this.trannum = trannum == null ? null : trannum.trim();
    }

    public String getStation() {
        return station;
    }

    public void setStation(String station) {
        this.station = station == null ? null : station.trim();
    }

    public String getOuttime() {
        return outtime;
    }

    public void setOuttime(String outtime) {
        this.outtime = outtime == null ? null : outtime.trim();
    }

    public Integer getDaytime() {
        return daytime;
    }

    public void setDaytime(Integer daytime) {
        this.daytime = daytime;
    }

    public Float getSiteprice() {
        return siteprice;
    }

    public void setSiteprice(Float siteprice) {
        this.siteprice = siteprice;
    }
}

StationMapper.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE mapper PUBLIC "-//mybatis.org//DTD Mapper 3.0//EN" "http://mybatis.org/dtd/mybatis-3-mapper.dtd">
<mapper namespace="com.cugb.dao.StationMapper">
  <resultMap id="BaseResultMap" type="com.cugb.model.Station">
    <id column="stationId" jdbcType="INTEGER" property="stationid" />
    <result column="tranNum" jdbcType="VARCHAR" property="trannum" />
    <result column="station" jdbcType="VARCHAR" property="station" />
    <result column="outTime" jdbcType="VARCHAR" property="outtime" />
    <result column="dayTime" jdbcType="INTEGER" property="daytime" />
    <result column="sitePrice" jdbcType="REAL" property="siteprice" />
  </resultMap>
  <sql id="Base_Column_List">
    stationId, tranNum, station, outTime, dayTime, sitePrice
  </sql>
  <select id="selectByPrimaryKey" parameterType="java.lang.Integer" resultMap="BaseResultMap">
    select 
    <include refid="Base_Column_List" />
    from stationInfo
    where stationId = #{stationid,jdbcType=INTEGER}
  </select>
  <delete id="deleteByPrimaryKey" parameterType="java.lang.Integer">
    delete from stationInfo
    where stationId = #{stationid,jdbcType=INTEGER}
  </delete>
  <insert id="insert" parameterType="com.cugb.model.Station">
    insert into stationInfo (stationId, tranNum, station, 
      outTime, dayTime, sitePrice
      )
    values (#{stationid,jdbcType=INTEGER}, #{trannum,jdbcType=VARCHAR}, #{station,jdbcType=VARCHAR}, 
      #{outtime,jdbcType=VARCHAR}, #{daytime,jdbcType=INTEGER}, #{siteprice,jdbcType=REAL}
      )
  </insert>
  <insert id="insertSelective" parameterType="com.cugb.model.Station">
    insert into stationInfo
    <trim prefix="(" suffix=")" suffixOverrides=",">
      <if test="stationid != null">
        stationId,
      </if>
      <if test="trannum != null">
        tranNum,
      </if>
      <if test="station != null">
        station,
      </if>
      <if test="outtime != null">
        outTime,
      </if>
      <if test="daytime != null">
        dayTime,
      </if>
      <if test="siteprice != null">
        sitePrice,
      </if>
    </trim>
    <trim prefix="values (" suffix=")" suffixOverrides=",">
      <if test="stationid != null">
        #{stationid,jdbcType=INTEGER},
      </if>
      <if test="trannum != null">
        #{trannum,jdbcType=VARCHAR},
      </if>
      <if test="station != null">
        #{station,jdbcType=VARCHAR},
      </if>
      <if test="outtime != null">
        #{outtime,jdbcType=VARCHAR},
      </if>
      <if test="daytime != null">
        #{daytime,jdbcType=INTEGER},
      </if>
      <if test="siteprice != null">
        #{siteprice,jdbcType=REAL},
      </if>
    </trim>
  </insert>
  <update id="updateByPrimaryKeySelective" parameterType="com.cugb.model.Station">
    update stationInfo
    <set>
      <if test="trannum != null">
        tranNum = #{trannum,jdbcType=VARCHAR},
      </if>
      <if test="station != null">
        station = #{station,jdbcType=VARCHAR},
      </if>
      <if test="outtime != null">
        outTime = #{outtime,jdbcType=VARCHAR},
      </if>
      <if test="daytime != null">
        dayTime = #{daytime,jdbcType=INTEGER},
      </if>
      <if test="siteprice != null">
        sitePrice = #{siteprice,jdbcType=REAL},
      </if>
    </set>
    where stationId = #{stationid,jdbcType=INTEGER}
  </update>
  <update id="updateByPrimaryKey" parameterType="com.cugb.model.Station">
    update stationInfo
    set tranNum = #{trannum,jdbcType=VARCHAR},
      station = #{station,jdbcType=VARCHAR},
      outTime = #{outtime,jdbcType=VARCHAR},
      dayTime = #{daytime,jdbcType=INTEGER},
      sitePrice = #{siteprice,jdbcType=REAL}
    where stationId = #{stationid,jdbcType=INTEGER}
  </update>
</mapper>

StationMapper.java

package com.cugb.dao;

import com.cugb.model.Station;

public interface StationMapper {
    int deleteByPrimaryKey(Integer stationid);

    int insert(Station record);

    int insertSelective(Station record);

    Station selectByPrimaryKey(Integer stationid);

    int updateByPrimaryKeySelective(Station record);

    int updateByPrimaryKey(Station record);
}