mybaits须要程序员自己编辑sql语句,mybatis官方提供逆向工程,可以本着单表自动生成mybatis执行所须求的代码(mapper.java,mapper.xml、pojo等)有了sql表的构造后, 我们就足以行使逆向工程直接扭转对应的Dao和JavaBean代码, 以及mapper.xml文件,那样可以大大减弱大家平时支出的工作量。
不过应用逆向工程局限性, 逆向工程措施只可以履行几遍, 假诺再一次实施就会一而再生成对应的Dao和JavaBean, 除非大家把前边生成的通通删除。那样对于代码的扩大性就不是很好, 即使大家要求对表结构进行改动, 那么咱们就非得对转移的Dao和JavaBean进行一个个改动,或者重新生成一份。
MyBatis Generator:简称MBG,是一个特意为MyBatis框架使用者定制的代码生成器,可以便捷的按照表生成相应的照耀文件,接口,以及bean类。援救大旨的增删改查,以及QBC风格的规则查询。可是表连接、
存储进度等那么些纷纷sql的概念必要大家手工编制。
文档查阅:
http://www.mybatis.org/generator/
官网下载:
下载步骤如下:
使用手续:
1、导入相关的jar包:那里帮助mysql,oracl
2、编写MBG的布局文件(首要几处配置)
1)jdbcConnection配置数据库连接音讯
2)javaModelGenerator配置javaBean的扭转策略
3)sqlMapGenerator 配置sql映射文件生成策略
4)javaClientGenerator配置Mapper接口的成形策略
5)table 配置要逆向分析的数据表(tableName:表名,domainObjectName:对应的javaBean名)
运行代码生成器生成代码注意Context标签,targetRuntime=“MyBatis3“可以生成带条件的增删改查,targetRuntime=“MyBatis3Simple“可以变更基本的增删改查,即便再一次转移,指出将从前生成的多寡删除,防止xml向后增添内容出现的标题。
<?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://192.168.61.22:3306/test" userId="root"
password="123456">
</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.softjx.model"
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.softjx.dao"
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.softjx.dao"
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 schema="test" tableName="school" domainObjectName="School"></table>
<table schema="test" tableName="student" domainObjectName="Student"></table>
</context>
</generatorConfiguration>
3、编译生成代码
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.xml.ConfigurationParser;
import org.mybatis.generator.exception.XMLParserException;
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.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);
}
public static void main(String[] args) throws Exception {
try {
GeneratorSqlmap generatorSqlmap = new GeneratorSqlmap();
generatorSqlmap.generator();
} catch (Exception e) {
e.printStackTrace();
}
}
}
4、导入用工具生成pojo,mapper.xml,接口文件,编写测试代码。
//测试
@Test
public void TestGetStudent() throws IOException {
try {
StudentMapper mapper=session.getMapper(StudentMapper.class);
System.out.println(mapper);
Student student=mapper.selectByPrimaryKey(3);
System.out.println(student.gettId() + " " + student.gettName() + " "+student.gettAge()+" "+student.gettEnterdate()+" "+student.gettSid());
} finally {
session.close();
}
}
//测试 (复杂条件测试)
@Test
public void TestGetStudent1() throws IOException {
try {
StudentMapper mapper=session.getMapper(StudentMapper.class);
System.out.println(mapper);
//1.查询所有:
/*
StudentExample example=null;
List<Student> students=mapper.selectByExample(example);
for(Student student :students)
System.out.println(student.gettId() + " " + student.gettName() + " "+student.gettAge()+" "+student.gettEnterdate()+" "+student.gettSid());
*/
//2.单个条件查询:
/*
StudentExample example=new StudentExample();
Criteria criteria= example.createCriteria();
criteria.andTAgeGreaterThan(60);
List<Student> students=mapper.selectByExample(example);
for(Student student :students)
System.out.println(student.gettId() + " " + student.gettName() + " "+student.gettAge()+" "+student.gettEnterdate()+" "+student.gettSid());
*/
//3.多条件查询and:
/*
StudentExample example=new StudentExample();
Criteria criteria= example.createCriteria();
criteria.andTAgeGreaterThan(20);
criteria.andTNameLike("%g%");
List<Student> students=mapper.selectByExample(example);
for(Student student :students)
System.out.println(student.gettId() + " " + student.gettName() + " "+student.gettAge()+" "+student.gettEnterdate()+" "+student.gettSid());
*/
//4.多条件查询or:
/*
StudentExample example=new StudentExample();
Criteria criteria= example.createCriteria();
criteria.andTAgeGreaterThan(20);
criteria.andTNameLike("%g%");
Criteria criteria1= example.createCriteria();
criteria1.andTSidLessThanOrEqualTo(1);
example.or(criteria1);
List<Student> students=mapper.selectByExample(example);
for(Student student :students)
System.out.println(student.gettId() + " " + student.gettName() + " "+student.gettAge()+" "+student.gettEnterdate()+" "+student.gettSid());
*/
//5.排序:
/*
StudentExample example=new StudentExample();
Criteria criteria= example.createCriteria();
criteria.andTAgeGreaterThan(20);
criteria.andTNameLike("%g%");
Criteria criteria1= example.createCriteria();
criteria1.andTSidLessThanOrEqualTo(1);
example.or(criteria1);
//example.setOrderByClause("t_id desc");
example.setOrderByClause("t_age desc,t_id asc");
List<Student> students=mapper.selectByExample(example);
for(Student student :students)
System.out.println(student.gettId() + " " + student.gettName() + " "+student.gettAge()+" "+student.gettEnterdate()+" "+student.gettSid());
*/
//6.统计
StudentExample example=new StudentExample();
Criteria criteria= example.createCriteria();
//criteria.andTAgeGreaterThan(60);
criteria.andTAgeGreaterThan(60);
criteria.andTNameLike("%g%");
int count=mapper.countByExample(example);
System.out.println(count);
} finally {
session.close();
}
}