代码不能直接copy运行，有些内容是为了说明知识点
1，sqlMqpConfig.xml
<?xml version="1.0" encoding="UTF-8" ?> <!DOCTYPE configuration PUBLIC "-//mybatis.org//DTD Config 3.0//EN" "http://mybatis.org/dtd/mybatis-3-config.dtd"> <configuration> <!-- 引入外部属性文件 --> <properties resource="jdbc.properties" /> <environments default="development"> <environment id="development"> <transactionManager type="JDBC" /> <dataSource type="POOLED"> <property name="driver" value="${jdbc.driverClassName}"/> <property name="url" value="${jdbc.url}"/> <property name="username" value="${jdbc.username}"/> <property name="password" value="${jdbc.password}"/> </dataSource> <!-- <dataSource type="POOLED"> <property name="driver" value="oracle.jdbc.driver.OracleDriver"/> <property name="url" value="jdbc:oracle:thin:@127.0.0.1:1521:orcl"/> <property name="username" value="scott"/> <property name="password" value="tiger"/> </dataSource> --> </environment> </environments> <!-- 指定映射文件或映射类 --> <mappers> <mapper resource="sqlMap/emp.xml"/> </mappers> </configuration>
2，log4j.properties
#在开发环境下，日志级别要设置成DEBUG，生产环境设置成info或error log4j.rootLogger=DEBUG, stdout #Console output... log4j.appender.stdout=org.apache.log4j.ConsoleAppender log4j.appender.stdout.layout=org.apache.log4j.PatternLayout log4j.appender.stdout.layout.ConversionPattern=%d{HH:mm:ss,SSS} [%c] - %m%n
3, jdbc.properties
jdbc.driverClassName=oracle.jdbc.driver.OracleDriver jdbc.url=jdbc:oracle:thin:@127.0.0.1:1521:orcl jdbc.username=scott jdbc.password=tiger
4, Emp.java
package com.mybatis.entity; public class Emp { private String ename; private int empno; private String job; public String getEname() { return ename; } public void setEname(String ename) { this.ename = ename; } @Override public String toString(){ return "Emp [ ename = " + ename + "; empno = " + empno + "]"; } public Emp(int empno, String ename, String job){ super(); this.empno = empno; this.ename = ename; this.job = job; } public int getEmpno() { return empno; } public void setEmpno(int empno) { this.empno = empno; } public String getJob() { return job; } public void setJob(String job) { this.job = job; } }
5, emp.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="test"> <!-- #{id}如果传入参数是简单类型，名称任意 --> <!-- ${}表示拼接字符串，将接收到的参数内容不加修饰拼接到sql中 会引起sql注入 ${value}:接收输入参数内容，如果是简单类型，只能使用${value} --> <select id="findEmpByEmpNo" parameterType="int" resultType="com.mybatis.entity.Emp"> select * from emp where empno =#{empno} </select> <select id="findEmpByJob" parameterType="java.lang.String" resultType="com.mybatis.entity.Emp"> select ename from emp where job =#{job} </select> <!-- 模糊查询 --> <select id="findByName" parameterType="java.lang.String", resultType="com.mybatis.entity.Emp"> select * from emp where empno like '%${value}%' </select> <!-- 输入类型参数是pojo，mybatis通过OGNL获取对象属性值 //比如java中：System.out.println(emp.getID()); // 检索时提交事务 //sqlSession.commit(); --> <insert id="save" parameterType="com.mybatis.entity.Emp"> <!-- 将插入数据的主键返回（比如自增主键时），返回到user对象中 SELECT LAST_INSERT_ID():得到insert进去记录的主键值，只适用于自增主键 注：单独使用时返回0 keyProperty：将查询到的主键值设置到parameterType指定的对象的那个属性中 order：SELECT LAST_INSERT_ID()执行顺序，相对于insert语句来说 --> <selectKey keyProperty="id" order="AFTER" resultType="java.lang.Integer"> SELECT LAST_INSERT_ID() </selectKey> <!-- 使用mysql的uuid()函数生成主键 执行过程：先使用uuid()获得主键，再将主键设置到user对象的id中 其次在insert执行时，从user对象中取得id属性 --> <selectKey keyProperty="id" order="BEFORE" resultType="java.lang.String"> SELECT UUID() </selectKey> 《此时需要传入id insert into emp(id,empno,ename,job) values (#{id},#{empno},#{ename},#{job}) insert into emp(empno,ename,job) values (#{empno},#{ename},#{job}) </insert> <update id="update" parameterType="com.mybatis.entity.Emp"> update emp set ename=#{ename} where empno=#{empno} </update> <delete id="delete" parameterType="int"> delete from emp where empno=#{empno} </delete> </mapper>
6, MybatisService.java
public class MybatisService { @Test public void findEmpByJobTest(){ //mybatis 配置文件 String resource = "SqlMapConfig.xml"; InputStream inputStream = null; SqlSession sqlSession = null; try { // 使用MyBatis提供的Resources类加载myBatis的配置文件(它也加载相关联的映射文件) inputStream = Resources.getResourceAsStream(resource); //构建sqlSession工厂 SqlSessionFactory sqlSessionFactory = new SqlSessionFactoryBuilder().build(inputStream); // 创建能执行映射文件中sql的sqlSession sqlSession = sqlSessionFactory.openSession(); // Emp emp = sqlSession.selectOne("test.findEmpByEmpNo", 7369); List<Emp> emp = sqlSession.selectList("test.findEmpByJob", "CLERK"); //System.out.println(emp.toString()); // 更新时时提交事务 //sqlSession.insert("test.save", emp); //sqlSession.commit(); //System.out.println(emp.getID()); System.out.println(emp); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } finally { if (sqlSession != null) { sqlSession.close(); } if (inputStream != null) { try { inputStream.close(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } } } } }
7, 另外
非自增主键返回（使用uuid）
使用mysql的uuid()函数生成主键，需要修改表中id类型为String
执行思路：
先通过uuid查到主键，将主键输入到insert语句中
执行uuid语句顺序在insert前