mybatis 核心配置文件
建议去看官网信息
https://mybatis.net.cn/configuration.html#properties
配置标签时注意编写顺序!!!
mybatis核心配置文件
<?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>
<environments default="development">
<environment id="development">
<transactionManager type="JDBC"/>
<dataSource type="POOLED">
<property name="driver" value="${driver}"/>
<property name="url" value="${url}"/>
<property name="username" value="${username}"/>
<property name="password" value="${password}"/>
</dataSource>
</environment>
</environments>
<mappers>
<mapper resource="org/mybatis/example/BlogMapper.xml"/>
</mappers>
</configuration>
对sql语句执行返回对象起别名
<typeAliases>
<typeAlias alias="Author" type="domain.blog.Author"/>
<typeAlias alias="Blog" type="domain.blog.Blog"/>
<typeAlias alias="Comment" type="domain.blog.Comment"/>
<typeAlias alias="Post" type="domain.blog.Post"/>
<typeAlias alias="Section" type="domain.blog.Section"/>
<typeAlias alias="Tag" type="domain.blog.Tag"/>
</typeAliases>
<typeAliases>
<package name="domain.blog"/>
</typeAliases>
与mapper对应的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.heima.wemedia.dao.WmChannelDao">
<resultMap type="com.heima.model.wemedia.entity.WmChannel" id="WmChannelMap">
<result property="id" column="id" jdbcType="INTEGER"/>
<result property="name" column="name" jdbcType="VARCHAR"/>
<result property="isDefault" column="is_default" jdbcType="INTEGER"/>
<result property="ord" column="ord" jdbcType="INTEGER"/>
<result property="description" column="description" jdbcType="VARCHAR"/>
<result property="status" column="status" jdbcType="INTEGER"/>
<result property="createdTime" column="CREATED_TIME" jdbcType="TIMESTAMP"/>
<result property="updatedTime" column="UPDATED_TIME" jdbcType="TIMESTAMP"/>
</resultMap>
<select id="queryById" resultMap="WmChannelMap">
select
id, name, is_default, ord, description, status, CREATED_TIME, UPDATED_TIME
from wm_channel
where id = #{id}
</select>
<delete id="deleteById">
delete from wm_channel where id = #{id}
</delete>
</mapper>
mapperlocaltion
顾名思义是一个定义mapper位置的属性 在yml或properties下配置,作用是实现mapper接口配置见mapper和接口的绑定。
mapper-locations: classpath:mapper/*.xml
则mapper-locations可以不用配置,配置也不会生效
但是,如果 当mapper接口和mapper接口对应的配置文件在
- 命名上不同或
- 所在的路径不同
之一不同,需要配置mapper-locations才能实现接口的绑定
主键返回
<insert id="add" useGeneratedKey="true" keyProperty="id">
</insert>
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