06、MyBatis 逆向工程

	<!-- <context>元素用於指定生成一組對象的環境。子元素用於指定要連接的資料庫，要生成的對象的類型以及要進行自檢的表。 -->
	<!-- targetRuntime="MyBatis3Simple":生成簡單版的CRUD -->
	<!-- targetRuntime="MyBatis3":生成複雜版的CRUD -->
	<!-- id:此上下文的唯一標識符。該值將在某些錯誤消息中使用。 -->
	<context id="DB2Tables" targetRuntime="MyBatis3">
	</context>

	<!-- jdbcConnection:指定如何連接到目標資料庫 -->
	<!-- MyBatis Generator使用JDBC的DatabaseMetaData類來發現您在配置中指定的表的屬性。-->
	<!-- 每個<context>元素都需要一個<connectionFactory>或<jdbcConnection >元素。 -->
		<jdbcConnection	driverClass="com.mysql.jdbc.Driver"
			connectionURL="jdbc:mysql://localhost:3306/mybatis?allowMultiQueries=true" 
			userId="root" 
			password="root123">
		</jdbcConnection>

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

		<!-- javaModelGenerator:指定javaBean的生成策略  -->
		<!-- targetProject:生成目標包名 -->
		<!-- targetProject:目標工程 -->
		<!-- http://mybatis.org/generator/configreference/javaModelGenerator.html -->
		<javaModelGenerator targetPackage="com.atguigu.mybatis.bean"
			targetProject=".\src">
			<property name="enableSubPackages" value="true" />
			<property name="trimStrings" value="true" />
		</javaModelGenerator>

• 如果指定sqlMapGenerator，則MBG將僅生成SQL映射XML文件和模型類。
• 如果您未指定sqlMapGenerator，則MBG將僅生成模型類。

		<!-- sqlMapGenerator:sql映射生成策略; -->
		<sqlMapGenerator targetPackage="com.atguigu.mybatis.dao"
			targetProject=".\conf">
			<property name="enableSubPackages" value="true" />
		</sqlMapGenerator>

		<!-- javaClientGenerator:指定mapper介面所在的位置 -->
		<!-- http://mybatis.org/generator/configreference/javaClientGenerator.html -->
		<javaClientGenerator type="XMLMAPPER"
			targetPackage="com.atguigu.mybatis.dao" targetProject=".\src">
			<property name="enableSubPackages" value="true" />
		</javaClientGenerator>

• MyBatis格式化的SQL Map文件
• 構成表“模型”的一組類，包括：

• 一個與表的主鍵匹配的類（如果表具有主鍵）。
• 一個類，用於匹配表中不在主鍵中的欄位和非BLOB欄位。如果有，該類將擴展主鍵。
• 一個用於保存表中任何BLOB欄位（如果有）的類。該類將擴展前兩個類之一，具體取決於表的配置。
• 一個用於在不同的“按示例”方法（selectByExample，deleteByExample）中生成動態where子句的類。

• （可選）MyBatis映射器界面

		<!-- 指定要逆向分析哪些表:根據表要創建javaBean -->
		<!-- http://mybatis.org/generator/configreference/table.html -->
    	<table tableName="tbl_dept" domainObjectName="Department"></table>
    	<table tableName="tbl_employee" domainObjectName="Employee"></table>

• 在 命令提示符下 使用XML配置
• 作為具有XML配置的Ant任務
• 作為Maven插件
• 從另一個具有XML配置的Java程式
• 從另一個具有基於Java的配置的Java程式
• 作為Eclipse功能

	@Test
	public void testMbg() throws Exception {
		   List<String> warnings = new ArrayList<String>();
		   boolean overwrite = true;
		   File configFile = new File("mbg.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);
	}

	@Test
	public void testSimple() throws IOException {
		SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
		SqlSession openSession = sqlSessionFactory.openSession();
		try {
			EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.class);
			List<Employee> list = mapper.selectAll();
			for (Employee employee : list) {
				System.out.println(employee.getId());
			}
		}finally {
			openSession.close();
		}
	}

	@Test
	public void testMyBatis3() throws IOException{
		SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
		SqlSession openSession = sqlSessionFactory.openSession();
		try{
			EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.class);
			//1.查詢所有ID
			List<Employee> emps = mapper.selectByExample(null);
//			for(Employee employee:emps) {
//				System.out.println(employee.getId());
//			}
			
			//2.查詢查詢員工名字中有e字母的和員工性別是1的 封裝員工查詢條件的example
			EmployeeExample example = new EmployeeExample();
			//創建一個Criteria,這個Criteria就是拼裝查詢條件;
			Criteria criteria = example.createCriteria();
			criteria.andLastNameLike("%e%");
			criteria.andGenderEqualTo("1");
			
			Criteria criteria2 = example.createCriteria();
			criteria2.andEmailLike("%e");
			example.or(criteria2);
			
			List<Employee> list = mapper.selectByExample(example);
			for(Employee employee:list) {
				System.out.println(employee.getId());
			}
			
		}finally{
			openSession.close();
		}
	}

package com.atguigu.mybatis.test;

import java.io.File;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.List;

import org.apache.ibatis.io.Resources;
import org.apache.ibatis.session.SqlSession;
import org.apache.ibatis.session.SqlSessionFactory;
import org.apache.ibatis.session.SqlSessionFactoryBuilder;
import org.junit.jupiter.api.Test;
import org.mybatis.generator.api.MyBatisGenerator;
import org.mybatis.generator.config.Configuration;
import org.mybatis.generator.config.xml.ConfigurationParser;
import org.mybatis.generator.internal.DefaultShellCallback;

import com.atguigu.mybatis.bean.Employee;
import com.atguigu.mybatis.bean.EmployeeExample;
import com.atguigu.mybatis.bean.EmployeeExample.Criteria;
import com.atguigu.mybatis.dao.EmployeeMapper;




class MyBatisTest {

	public SqlSessionFactory getSqlSessionFactory() throws IOException {
		String resource = "mybatis-config.xml";
		InputStream inputStream = Resources.getResourceAsStream(resource);
		
		return new SqlSessionFactoryBuilder().build(inputStream);
	}
	 
	@Test
	public void testMbg() throws Exception {
		   List<String> warnings = new ArrayList<String>();
		   boolean overwrite = true;
		   File configFile = new File("mbg.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);
	}
	
//	@Test
//	public void testSimple() throws IOException {
//		SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
//		SqlSession openSession = sqlSessionFactory.openSession();
//		try {
//			EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.class);
//			List<Employee> list = mapper.selectAll();
//			for (Employee employee : list) {
//				System.out.println(employee.getId());
//			}
//		}finally {
//			openSession.close();
//		}
//	}
	
	@Test
	public void testMyBatis3() throws IOException{
		SqlSessionFactory sqlSessionFactory = getSqlSessionFactory();
		SqlSession openSession = sqlSessionFactory.openSession();
		try{
			EmployeeMapper mapper = openSession.getMapper(EmployeeMapper.class);
			//1.查詢所有ID
			List<Employee> emps = mapper.selectByExample(null);
//			for(Employee employee:emps) {
//				System.out.println(employee.getId());
//			}
			
			//2.查詢查詢員工名字中有e字母的和員工性別是1的 封裝員工查詢條件的example
			EmployeeExample example = new EmployeeExample();
			//創建一個Criteria,這個Criteria就是拼裝查詢條件;
			Criteria criteria = example.createCriteria();
			criteria.andLastNameLike("%e%");
			criteria.andGenderEqualTo("1");
			
			Criteria criteria2 = example.createCriteria();
			criteria2.andEmailLike("%e");
			example.or(criteria2);
			
			List<Employee> list = mapper.selectByExample(example);
			for(Employee employee:list) {
				System.out.println(employee.getId());
			}
			
		}finally{
			openSession.close();
		}
	}
	
	
}