mybatis配置到基础使用
基础配置文件
jdbc.properties
jdbc.driverClassName = com.mysql.jdbc.Driver
jdbc.url = jdbc:mysql://localhost:3306/mybatis?useUnicode=true&characterEncoding=utf8&useSSL=false&autoReconnect=true&allowMultiQueries=true
jdbc.username = root
jdbc.password = root
mybatis-config
<?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">
<!--配置-->
<configuration>
<!--属性-->
<!-- <properties></properties>-->
<!--设置-->
<settings>
<!--设置启用数据库字段下划线映射到java对象的驼峰式命名属性，默认为false-->
<setting name="mapUnderscoreToCamelCase" value="true"/>
</settings>
<!-- 类型命名-->
<typeAliases>
<typeAlias type="com.soft1851.spring.mybatis.entity.Forum" alias="Forum"></typeAlias>
<typeAlias type="com.soft1851.spring.mybatis.entity.Clazz" alias="Clazz"></typeAlias>
<typeAlias type="com.soft1851.spring.mybatis.entity.Course" alias="Course"></typeAlias>
<typeAlias type="com.soft1851.spring.mybatis.entity.CourseStudent" alias="CourseStudent"></typeAlias>
<typeAlias type="com.soft1851.spring.mybatis.entity.Student" alias="Student"></typeAlias>
<typeAlias type="com.soft1851.spring.mybatis.entity.Teacher" alias="Teacher"></typeAlias>
</typeAliases>
<!--类型处理器-->
<!-- <typeHandlers></typeHandlers>-->
<!--对象工厂-->
<!-- <objectFactory type=""/>-->
<!--插件-->
<!-- <plugins>-->
<!-- <plugin interceptor=""></plugin>-->
<!-- </plugins>-->
<!--配置环境-->
<!-- <environments default="">-->
<!--环境变量-->
<!-- <environment id="">-->
<!--事务管理器-->
<!-- <transactionManager type=""></transactionManager>-->
<!--数据源-->
<!-- <dataSource type="">-->
<!-- </dataSource>-->
<!-- </environment>-->
<!-- </environments>-->
<!--数据库厂商标识-->
<!-- <databaseIdProvider type=""/>-->
<!--映射器-->
<!-- <mapperss></mappers>-->
</configuration>
spring-mybatis
<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xmlns:context="http://www.springframework.org/schema/context"
xmlns:aop="http://www.springframework.org/schema/aop"
xmlns:p="http://www.springframework.org/schema/p"
xmlns:tx="http://www.springframework.org/schema/tx"
xsi:schemaLocation="http://www.springframework.org/schema/beans
http://www.springframework.org/schema/beans/spring-beans.xsd
http://www.springframework.org/schema/context
https://www.springframework.org/schema/context/spring-context.xsd
http://www.springframework.org/schema/aop
https://www.springframework.org/schema/aop/spring-aop.xsd
http://www.springframework.org/schema/tx
http://www.springframework.org/schema/tx/spring-tx.xsd">
<!--读取外部的数据库属性文件-->
<context:property-placeholder location="classpath:jdbc.properties"/>
<!--扫描含有注解的包-->
<context:component-scan base-package="com.soft1851.spring.mybatis.service.impl"/>
<!-- 启动上下文的注解配置 -->
<context:annotation-config/>
<!-- 启动AOP支持 -->
<aop:aspectj-autoproxy/>
<!-- 创建dataSource对象 -->
<bean id="dataSource"
class="com.alibaba.druid.pool.DruidDataSource">
<property name="driverClassName" value="${jdbc.driverClassName}" />
<property name="url" value="${jdbc.url}" />
<property name="username" value="${jdbc.username}" />
<property name="password" value="${jdbc.password}" />
<property name="initialSize" value="1"/>
<property name="minIdle" value="1"/>
<property name="maxActive" value="20"/>
<property name="maxWait" value="60000"/>
<property name="timeBetweenEvictionRunsMillis" value="60000"/>
<property name="minEvictableIdleTimeMillis" value="300000"/>
<property name="poolPreparedStatements" value="true"/>
</bean>
<!-- 在springIOC容器中创建mybatis核心类sqlSessionFactor -->
<bean id="sqlSessionFactory"
class="org.mybatis.spring.SqlSessionFactoryBean">
<!-- 需要 dataSource -->
<property name="dataSource" ref="dataSource"/>
<!-- 引入mybatis配置文件 -->
<property name="configLocation" value="classpath:mybatis-config.xml"/>
<!--指定实体类所在包-->
<property name="typeAliasesPackage" value="com.soft1851.spring.mybatis.entity" />
<!-- 自动扫描mapping.xml文件 -->
<property name="mapperLocations" value="classpath:mappers/*.xml"/>
</bean>
<!-- 通过Mapper扫描器MapperScannerConfigurer，批量将 basePackage指定包中的接口全部生成Mapper动态代理对象 -->
<bean class="org.mybatis.spring.mapper.MapperScannerConfigurer">
<property name="basePackage" value="com.soft1851.spring.mybatis.mapper"/>
<property name="sqlSessionFactoryBeanName" value="sqlSessionFactory">
</property>
</bean>
<!--事务管理器配置 -->
<bean id="manager" class="org.springframework.jdbc.datasource.DataSourceTransactionManager"
p:dataSource-ref="dataSource"/>
<!-- 使用声明式事务 -->
<tx:annotation-driven transaction-manager="manager"/>
</beans>
xxxMapper.xml文件
<?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.soft1851.spring.mybatis.mapper.StudentMapper">
<insert id="insert" parameterType="Student" useGeneratedKeys="true" keyProperty="studentId">
INSERT INTO t_student(clazz_id,student_name,hometown,birthday)
VALUES (#{clazzId},#{studentName},#{hometown},#{birthday})
</insert>
<delete id="delete" parameterType="int">
DELETE
FROM t_student
WHERE student_id =#{studentId}
</delete>
<select id="getStudentById" parameterType="int" resultType="Student">
SELECT * FROM
t_student
WHERE student_id = #{studentId}
</select>
<!-- 注意修改语句的逗号-->
<update id="update" parameterType="Student">
UPDATE t_student
SET student_name =#{studentName},
hometown=#{hometown},
birthday=#{birthday}
WHERE student_id =#{studentId}
</update>
<insert id="batchInsert" parameterType="Student">
INSERT INTO t_student VALUES
<foreach collection="students" item="item" index="index" separator=",">
(#{item.studentId},#{item.clazzId},#{item.studentName},#{item.hometown},#{item.birthday})
</foreach>
</insert>
<delete id="batchDelete" parameterType="int">
DELETE FROM t_Student
WHERE student_id IN
<foreach item="item" index="index" collection="idList" open="(" separator="," close=")">
#{item}
</foreach>
</delete>
<update id="batchUpdate" parameterType="java.util.List">
<foreach collection="students" item="item" index="index" open="" close="" separator=";">
UPDATE t_student t
<set>
t.student_name=#{item.studentName}
</set>
</foreach>
</update>
<select id="selectLimit" resultType="Student">
SELECT student_id,clazz_id,student_name,hometown,birthday
FROM t_student
WHERE clazz_id=${2} AND hometown like '%江苏%'
</select>
<select id="selectLimitByDynamicSql" parameterType="Student" resultType="Student">
SELECT student_id,clazz_id,student_name,hometown,birthday
FROM t_student
<!-- <where>-->
<!-- <if test="clazzId!=null">-->
<!-- clazz_id=#{clazzId}-->
<!-- </if>-->
<!-- <if test="hometown!=null">-->
<!-- AND hometown like "%"#{hometown}"%"-->
<!-- </if>-->
<!-- <if test="studentName!=null">-->
<!-- AND student_name like #{studentName}-->
<!-- </if>-->
<!-- </where>-->
WHERE 1=1
<choose>
<when test="clazzId!=null">
AND clazz_id=#{clazzId}
</when>
<when test="hometown !=null">
AND hometown like "%"#{hometown}"%"
</when>
<otherwise>
AND student_id > ${0}
</otherwise>
</choose>
</select>
</mapper>
整体代码结构
mapper层代码编写格式
package com.soft1851.spring.mybatis.mapper;
import com.soft1851.spring.mybatis.entity.Forum;
import java.util.List;
/**
* @author Johnny
* @Date: 2020/3/30 20:46
* @Description:
*/
public interface ForumMapper {
/**
* 新增实体
* @param forum
*/
void insert(Forum forum);
/**
* 根据id删除
* @param id
*/
void delete(int id);
/**
* 修改
* @param forum
*/
void update(Forum forum);
/**
* 查询所有
* @return
*/
List<Forum> selectAll();
/**
* 根据id查询Forum
* @param id
* @return Forum
*/
Forum selectForumById(int id);
}
xml数据库语句的编写格式
增
<insert id="insert" parameterType="Student" useGeneratedKeys="true" keyProperty="studentId">
INSERT INTO t_student(clazz_id,student_name,hometown,birthday)
VALUES (#{clazzId},#{studentName},#{hometown},#{birthday})
</insert>
删
<delete id="delete" parameterType="int">
DELETE
FROM t_student
WHERE student_id =#{studentId}
</delete>
查
<select id="getStudentById" parameterType="int" resultType="Student">
SELECT * FROM
t_student
WHERE student_id = #{studentId}
</select>
改
<update id="update" parameterType="Student">
UPDATE t_student
SET student_name =#{studentName},
hometown=#{hometown},
birthday=#{birthday}
WHERE student_id =#{studentId}
</update>
foreach
<insert id="batchInsert" parameterType="Student">
INSERT INTO t_student VALUES
<foreach collection="students" item="item" index="index" separator=",">
(#{item.studentId},#{item.clazzId},#{item.studentName},#{item.hometown},#{item.birthday})
</foreach>
</insert>