mybatis 大于_酸爽！IDEA 中这么玩 MyBatis，让编码速度飞起！

作者：Orson
cnblogs.com/java-class/p/6237564.html

1. 搭建 MyBatis Generator 插件环境
- a. 添加插件依赖 pom.xml
- b. 配置文件 generatorConfig.xml
- c. 数据库配置文件 jdbc.properties
- d. 配置插件启动项
2.项目实战
- a. 比如在一个项目我们要删除某个小组下某个用户的信息
- b. 根据小组ID(非主键更新小组信息)
- c. 各种查询

IDEA 逆向 MyBatis 工程时，不像支持 Hibernate 那样有自带插件，需要集成第三方的 MyBatis Generator。

MyBatis Generator的详细介绍 http://mybatis.github.io/generator/index.html

本篇博客图解 MyBatis Generator 的使用过程，并结合实战说明逆向工程的使用方式。

1. 搭建 MyBatis Generator 插件环境

a. 添加插件依赖 pom.xml

          
            <plugin>
                <groupId>org.mybatis.generatorgroupId>
                <artifactId>mybatis-generator-maven-pluginartifactId>
                <version>1.3.2version>
                <configuration>
                    <configurationFile>src/main/resources/generatorConfig.xmlconfigurationFile>
                    <verbose>trueverbose>
                    <overwrite>trueoverwrite>
                configuration>
                <executions>
                    <execution>
                        <id>Generate MyBatis Artifactsid>
                    execution>
                executions>
                <dependencies>
                    <dependency>
                        <groupId>org.mybatis.generatorgroupId>
                        <artifactId>mybatis-generator-coreartifactId>
                        <version>1.3.2version>
                    dependency>
                dependencies>
            plugin>

b. 配置文件 generatorConfig.xml

<?xml  version="1.0" encoding="UTF-8"?>
generatorConfiguration
        PUBLIC "-//mybatis.org//DTD MyBatis Generator Configuration 1.0//EN"
        "http://mybatis.org/dtd/mybatis-generator-config_1_0.dtd">
<generatorConfiguration>
    <properties resource="jdbc.properties"/>
    <classPathEntry location="${jdbc_driverLocation}"/> 

    <context id="default" targetRuntime="MyBatis3">
        
        <commentGenerator>
            <property name="suppressDate" value="true"/>
            <property name="suppressAllComments" value="true"/>
        commentGenerator>

        
        <jdbcConnectiondriverClass="${jdbc_driverClass}"connectionURL="${jdbc_url}"userId="${jdbc_user}"password="${jdbc_pwd}">
        jdbcConnection>

        
        <javaTypeResolver><property name="forceBigDecimals" value="false"/>javaTypeResolver>

        
        <javaModelGenerator targetPackage="com.rambo.sdm.dao.pojo" targetProject="src/main/java">
            
            <property name="enableSubPackages" value="false"/>
            
            <property name="constructorBased" value="true"/>
            
            <property name="trimStrings" value="true"/>
            
            <property name="immutable" value="false"/>
        javaModelGenerator>

        
        <sqlMapGenerator targetPackage="com.rambo.sdm.dao.mapper" targetProject="src/main/java">
            <property name="enableSubPackages" value="false"/>
        sqlMapGenerator>

        
        <javaClientGenerator targetPackage="com.rambo.sdm.dao.inter" targetProject="src/main/java" type="XMLMAPPER">
            <property name="enableSubPackages" value="true"/>
        javaClientGenerator>

        <table tableName="user" domainObjectName="UserPO">
            <generatedKey column="uuid" sqlStatement="SELECT REPLACE(UUID(),'-','') UUID FROM DUAL"/>
        table>
    context>
generatorConfiguration>

c. 数据库配置文件 jdbc.properties

jdbc_driverLocation=D:\\Program Files\\Repository\\mysql\\mysql-connector-java\\5.1.38\\mysql-connector-java-5.1.38.jar
jdbc_driverClass=com.mysql.jdbc.Driver
jdbc_url=jdbc:mysql://localhost:3306/db_test?useUnicode=true&characterEncoding=utf-8
jdbc_user=root
jdbc_pwd=123456
validationQuery = select 1

d. 配置插件启动项

2.项目实战

User类就是普通的实体类，定义了数据库对应的字段，以及set/get方法

Mybatis 引入了 Example 类，用来封装数据库查询条件。

a. 比如在一个项目我们要删除某个小组下某个用户的信息

    public int deleteUserApplyInfo(long user_id,long team_id){
        StudyTeamUserApplyInfoExample ue = new StudyTeamUserApplyInfoExample();
        ue.createCriteria().andUserIdEqualTo(new BigDecimal(user_id)).andTeamIdEqualTo(new BigDecimal(team_id));
        return studyTeamUserApplyInfoDAO.deleteByExample(ue);
    }

b. 根据小组ID(非主键更新小组信息)

   public int updateStudyTeamInfo(StudyTeamInfo st){
        StudyTeamInfoExample ste = new StudyTeamInfoExample();
        ste.createCriteria().andTeamIdEqualTo(st.getTeamId());
        return studyTeamInfoDAO.updateByExampleSelective(st,ste);
    }

c. 各种查询

(1)模糊查询并且排序

public List getStudyTeamInfoByName(String team_name){
        StudyTeamInfoExample se = new StudyTeamInfoExample();
        se.createCriteria().andTeamNameLike("%"+team_name+"%").andEnableEqualTo((short)1);
        se.setOrderByClause("team_score desc");
        List ls = studyTeamInfoDAO.selectByExample(se);if(ls!=null&&ls.size()>0){return ls;
        }return null;
    }

(2)大于等于某个分数并且小于某个分数的查询

public StudyTeamLevel getStudyTeamLevel(long score){
        StudyTeamLevelExample le = new StudyTeamLevelExample();
        le.createCriteria().andNeedScoreLessThanOrEqualTo(score).andUpScoreGreaterThan(score);
        List ls = studyTeamLevelDAO.selectByExample(le);if(ls!=null&&ls.size()>0){return ls.get(0);

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